In December 1640, Portugal rebelled against Philip IV. From that point until 1668, Portugal and Spain were engaged in a global-scale war that precipitated a drastic reconfiguration of the Atlantic world. One of the boldest decisions taken by the Spanish Empire during this period was the suspension of the transatlantic slave trade.1 This measure aimed to obstruct the primary channel through which Portuguese subjects infiltrated the economies of Spanish America. However, this decision against the Portuguese slave traders did not occur in isolation. Rather than being a radical measure enacted solely within the context of war, it should be understood as the culmination of a process rooted in developments from the 1630s. During this earlier period, royal institutions and officials, both in the Iberian Peninsula and the Americas, increasingly resorted to the Inquisition as a tool to constrain the economic ascendancy of Portuguese asentistas. This was achieved through actions such as seizing their fortunes, threatening their families, or compelling them to collaborate with the Crown.2
The suspension of the official transatlantic slave trade had a profound impact on the Spanish Caribbean. Until the early 1650s, only a small number of enslaved Africans reached these colonies. In the absence of new enslaved African labour force, Spanish American colonists resorted to intra-colonial purchases to fill the labour gap. Simultaneously, indigenous enslavement became increasingly significant, both in terms of territorial scope and number of individuals enslaved. This development was accompanied by an intensification of the trade in locally born enslaved people of African descent, as well as older acculturated African slaves who had been transported to Spanish America before the suspension of the trade.3 Although the suspension initially appeared effective, in the short and medium term, the high demand for labour, coupled with mounting dissatisfaction in the Spanish American colonies, ultimately prompted the Crown to re-open the transatlantic slave trade in 1651 – seventeen years before the conclusion of the war with Portugal in 1668.
For Portuguese slave traders, the consequences of the suspension of the Spanish transatlantic slave trade were far from uniform and varied by region. By the end of the first decade of suppression, Portuguese slaving networks had lost their dominant role in controlling the distribution of slaves to the Spanish Caribbean. The vacuum created by their diminished presence was gradually filled by private Dutch traders, who aligned their interests with those of Spanish American slave traders and local officials in the Caribbean.4 By the time the ban was lifted, Portuguese networks had largely lost their prominence in the slave trade to the Spanish Caribbean. Their primarily familial networks had been replaced by business partnerships organised out of Amsterdam and Middelburg. Nevertheless, Portuguese networks were not uniformly affected. In the South Atlantic, they managed to maintain their dominance, significantly increasing their participation in the slave trade between Angola, the Rio de la Plata region, and Brazil, a circuit that had previously been off-limits under the legal framework of the Monarchy prior to 1640.5
The specific reasons that led the Spanish Monarchy to re-open the slave imports into Spanish American markets in 1651 remain unclear, though a constellation of imperatives appears to have influenced this decision. The first imperative was fiscal. The decline in slave imports to the Spanish Caribbean had significantly reduced the revenue of local institutions and the Monarchy itself. Traditionally, the high demand for enslaved labour ensured that major Spanish Caribbean ports facilitated the cyclical provision of markets, becoming efficient hubs for tax collection and generating a steady stream of revenue. The second imperative arose from Spanish America itself. The Crown faced mounting pressure from most Spanish American cities, which issued a continuous wave of complaints to the Consejo de Indias in Madrid from 1645 onwards, emphasising the detrimental effects of labour shortages on local and regional economies. The third imperative, though historiographically contested, may have been the need for a political rapprochement between the Spanish Empire and the United Provinces following the Peace of Münster (1648) and the conclusion of the Eighty Year’s War. The end of the war brought an increased presence of Dutch fleets and mariners in the Caribbean, raising concerns among Spanish colonial officials about unregulated Dutch penetration of the Spanish Caribbean markets, a phenomenon that had developed since the 1630s.6
The Spanish Empire’s position towards Dutch merchants remained ambiguous. While formal trade between the colonies of both countries in the Caribbean was prohibited in 1651, new legislation introduced loopholes that allowed for legal trade. Most notably, from 1648 onwards, Dutch ships were granted the right to call at Spanish Caribbean ports in cases of emergency or distress. For Dutch captains and shipmasters, this clause provided a convenient pretext to call at Spanish Caribbean ports under the guise of distress, sell their cargoes, and receive payment in silver or commodities such as indigo, cochineal, sugar, or tobacco. For the local population, the arrival of Dutch ships offered valuable opportunities to barter locally produced goods for enslaved Africans and European or Asian merchandise. Over the following decades, this system, known as arribada forzosa, became endemic.7
While arribada forzosa provided some relief for the growing demand for enslaved labour, it was insufficient. Consequently, the Crown was compelled to explore alternative means to supply the Spanish American markets. From 1651 to 1663, the Monarchy opted to organise the official slave trade through a licensing system overseen by the Consejo de Indias and the Casa de la Contratación. The reasons why the Consejo chose direct administration over an asiento with an asentista or a commercial partnership remain unclear. However, this licensing reflected a balancing act: on the one hand, the Crown sought to maintain political and economic exclusion while incorporating fiscal revenues; on the one hand, it aimed to address growing competition in the Atlantic, particularly from Dutch and English traders, by encouraging merchants to invest directly in the official slave trade through legal means.
During the licensing period, the Crown sought to maximise the premiums collected for each licence. However, prices for licences remained at 1640 levels. As was customary before the 1640s, licences could be paid for in installments. Unlike earlier practices, however, payments during this period could only be made in Spain, rather than across the Iberian Peninsula and in Spanish America. This measure was likely designed to hinder the circulation and transfer of capital between Spanish American colonies, as well as between these colonies and Caribbean towns beyond the territorial control of the Spanish Empire, and between Spanish Caribbean ports and Spain.8
The restructured framework for the slave trade was designed to prevent inter- and intra-imperial interactions in the Caribbean. To achieve this primary objective, licence holders were permitted to sail to the West Coast of Africa to purchase enslaved Africans. Spanish captains were authorised to enlist up to six Portuguese subjects as part of their crews, a measure aimed at facilitating the procurement of captives in Africa, given that Portuguese and Luso-Africans controlled specific slave markets along the coast, often beyond the reach of Portuguese-controlled territories. In effect, the importation of enslaved Africans into the Spanish Caribbean after 1651 became a Spanish enterprise mediated by Portuguese brokers aboard Spanish ships. These brokers served as intermediaries between Spanish captains and Africa-based Portuguese and Luso -African merchants, operating within a legal framework. However, the apparent choice to trade directly with Portuguese subjects in Africa is misleading. Neither the Spanish Crown, nor the licensed captains had a genuine alternative. By the 1650s, the English presence in Africa was weak, and the Dutch had lost significant ground following defeats in São Tomé and Angola to the Portuguese in 1641 and 1647, respectively. The WIC retained only Elmina (former Castelo da Mina) as its sole noteworthy African outpost.9
To make the licensing system more attractive to slave traders and other investors, the Consejo de Indias allowed licence holders to name their preferred port of disembarkation in Spanish America, submitting requests to the Conselho for approval. This flexibility regarding Caribbean ports resulted in significant losses for Cartagena and Veracruz, which had traditionally been the privileged and exclusive destinations for slaving ships. Alongside the loss of trade came diminished fiscal revenue, reduced local employment, and a decline in these ports’ prominence as redistributive hubs of enslaved labour to the Spanish American hinterlands. Ultimately, the erosion of Cartagena’s and Veracruz’s privileged positions marked a transition from a system of concentrated markets for the trade and distribution of enslaved Africans to one of more diffused markets. This shift reshaped local and regional social and economic networks of distribution.
Despite the Crown’s efforts, only a minority of traders participated in the official trade. Between 1651 and 1663, when the licensing system was operational, at least 15,147 enslaved Africans were transported to the Spanish Caribbean, primarily through smuggling and contraband.10 At times, the unofficial trade surpassed the official trade by a factor of seven. For instance, between 1651 to 1654, the total number of slaves authorised by licences was approximately 910, while the actual number of disembarked captives reached 6,453.11 Smuggling was not the only factor undermining royal revenues; licence holders themselves often violated regulations by exceeding their authorised quotas. In one instance, Juan Bautista Pluma, shipmaster of the Nuestra Señora de Guadalupe, received permission to transport 150 captives to “any port in the Indies”.12 However, when his ship reached Santo Domingo in 1656, it carried 259 captives.13
A critical factor in the rise of smuggling during this period was the Crown’s limited capacity to enforce the official trade. Spanish American authorities were generally inclined to facilitate the activities of slave traders, whether they operated official licences or through unofficial channels. Ironically, the reopening of official markets appears to have boosted smuggling and contraband. The legalisation of the trade normalised the presence of enslaved individuals as commodities, making it easier to justify their presence aboard ships, even when those vessels lacked authorisation for slave trading. Following the dismantling of the traditional Portuguese system, new transatlantic and regional slave trade networks emerged during the 1650s to supply the Spanish Caribbean.
1 Changing the Rules of the Game: The 1662 Asiento
The Crown’s efforts to revitalise the official slave trade during the 1650s proved unsuccessful. The immediate outcome was limited revenue from taxes and duties. Smuggling became more significant than ever, and the actors who had emerged during the unofficial circuits of the 1640s further consolidated their positions. Meanwhile, the Crown’s urgent need for revenue persisted. After the conclusion of the war with France in 1659, military deployment was redirected towards the ongoing conflict with Portugal. This period of chronic shortages saw various attempts to secure short-term funding and restructure the fiscal system.14 It was within this context that a new asiento for the slave trade was negotiated.
The new asiento, signed in June 1662, represented an agreement between the Consejo de Indias and the Genoese firm of Domenico Grillo and Ambrosio Lomellino. This contract marked a turning point in the organization of the slave trade within the Spanish Empire. More importantly, it established a framework that would shape the trade until the mid-eighteenth century. The norms governing the operation of the trade changed, as did the role of the asientista.
Among the numerous innovations introduced by the 1662 asiento, four were particularly significant in reshaping the slave trade to Spanish America. First, this asiento established the monopolistic management of the trade, referred to by contemporaries as an estanco. This change granted a single entity exclusive rights to manage the African slave trade to Spanish America. Previously, the ‘Portuguese asientos’ had allowed multiple actors to participate by acquiring licences from the Crown, the Casa de Contratación, or companies farming out the licence market, colloquially known as asentistas. Until 1662, the system had permitted the official participation of multiple actors in the slave trade.
Second, the new asiento introduced the possibility of importing enslaved Africans from Caribbean outposts rather than directly from the West Coast of Africa. These Caribbean markets were beyond the territorial sovereignty of the Habsburg Crown and governed by rival states such as England and the Dutch Republic. In this context, the importation of enslaved Africans into Spanish America became inherently trans-imperial, with the political and operational choice of where this trade would occur assuming critical importance. Following the Peace of Münster (1648), the Spanish Empire officially recognised the Dutch presence in the Americas, but the asiento facilitated regular, substantial and legal exchanges between Curaçao and the Spanish American Main. Additionally, the English presence in the Caribbean was implicitly acknowledged by the Spanish Empire through the asiento. Although Jamaica was captured by the English in 1655 and its sovereignty formally recognized by Madrid only in 1670, Jamaica had already begun supplying the asiento of Grillo and Lomellino with enslaved Africans. In sum, under this new operational framework, the asiento fostered the emergence of Curaçao and Jamaica as major trade hubs within the Dutch and the English empires, respectively.15
Third, the criteria for selecting suppliers for the asiento became increasingly tied with international politics rather than the complex social negotiations traditionally conducted between the Spanish Monarchy and some of its subjects. The contract stipulated that only subjects of monarchs and republics at peace with the Spanish Monarchy were eligible as suppliers. Consequently, during the administration of Grillo and Lomellino, Portuguese suppliers were excluded until 1668, and French suppliers were barred between 1667 and 1668, while Dutch and English suppliers were deemed eligible.
Finally, a fourth and significant change pertained to the institutional organisation of the slave trade within the Spanish Atlantic. Before 1662, the slave trade fell under the jurisdiction of the Casa de la Contratación and the Spanish American audiencias, similar to other transatlantic trades. The Grillo and Lomellino asiento, however, was placed under an autonomous legal framework overseen by the Consejo de Indias, the highest court for American affairs. This restructuring removed the Casa de la Contratación and the audiencias from their roles in overseeing the slave trade and the jurisdiction over the asiento. As a result, asiento operations were shielded from interference by Spanish American authorities, who had vested interests in the unofficial slave trade.
The Crown implemented these changes to bolster and secure fiscal revenues. The Genoese firm agreed to deliver 3,500 piezas de Indias annually for seven years (eventually extended to eleven years), paying 100 pesos for each pieza imported into Spanish America. The pieza de Indias standard was defined as a healthy enslaved adult, measuring seven cuartas in height and free from physical defects. By paying this fixed rate, Grillo and Lomellino were exempted from all other taxes or duties related to the slave trade. Consequently, the Crown deprived Spanish American city councils of an important source of revenue.
The 1662 asiento was therefore conceived as a strategy to address one of the most pressing challenges faced by early modern global empires: the extraction of resources from specific geographical locations to be mobilised and expended elsewhere. In negotiating the asiento, Grillo and Lomellino offered a solution to this problem by promising to supply a significant number of warships to Spain in exchange for monopolistic control over the slave trade to Spanish America. Despite their lack of prior experience in the slave trade, transatlantic commerce, or shipbuilding, the Crown awarded the asiento to the firm, relying on its reputation as one of the most prominent international banking houses, with extensive experience in tax-farming in Spain.
The Crown’s urgent need for ships gave Grillo and Lomellino considerable leverage in the asiento negotiations. However, the firm’s primary interest lay not in shipbuilding but in gaining access to the asiento de negros. Consequently, Grillo and Lomellino sought to extricate themselves from their shipbuilding obligations as quickly as possible. After extensive petitioning, they persuaded the Crown’s councils to cancel the construction of four ships in the Basque Country, substituting these with vessels imported from the Dutch Republic.16 Of the six ships originally contracted, only four were ever completed.17 To compensate the Crown, Grillo and Lomellino provided loans to fund the army in Flanders, which was under significant strain by 1667 during the War of Devolution (1667–1668). These loans aligned more closely with the firm’s expertise as financiers and were less costly and logistically complex than direct involvement in shipbuilding in northern Spain.
For Grillo and Lomellino, the asiento represented a unique opportunity to gain access to Spanish America and its silver resources. This was particularly significant for Genoese entrepreneurs, who lacked the backing of their home state for overseas ventures. From the perspective of Genoese mercantile and financial networks, the asiento was a highly valuable asset, compensating for the disruption of traditional channels through which they accessed silver, primarily as bankers to the Spanish Crown. Although Portuguese financiers had dominated the Crown’s banking sector in the 1620s, the Crown’s 1648 bankruptcy severely undermined Portuguese solvency, creating opportunities for other financiers, such as Grillo and Lomellino.
Lending money to the Spanish Crown was less attractive in the late 1640s than it had been previously, as systematic payments in American silver, a common practice in the restitution of state loans, ceased in 1654.18 Furthermore, starting in the mid-1650s and continuing through the 1660s, the Genoese faced a shifting set of financial demands from the Crown. These changes created new business opportunities for which the Genoese were less prepared compared to other competitors, particularly Spanish merchant-bankers. While the Genoese excelled in international finance, where silver circulated abundantly, the Crown primarily required copper coin (vellón) during this period to finance its war against Portugal (1640–1668) and France (1635–1659). Additionally, the Spanish Empire increasingly relied on diplomacy rather than military interventions in its European relations, further reducing the demand for international loans in silver. Despite consolidating their position as the leading international bankers to the Crown until the 1680s, Genoese merchant-bankers experienced a significant decline in returns from their assistance to the Spanish Empire after the 1660s.19
In response to these changes in international financial markets, the Genoese sought alternative economic niches that provided more secure and profitable access to silver. Some Genoese banking firms invested in public debt in Venice, the Austrian Habsburg Empire, or the Papal states.20 Others turned their attention to provisioning the Spanish and Portuguese transatlantic trading systems. The openness of the Iberian empires to foreign merchants, combined with the Genoese’s long-standing familiarity within Iberian societies, facilitated this shift. Nevertheless, the Genoese faced increasing competition from Dutch, French and English merchants in the main Iberian cities, as these groups redirected overseas trade from Lisbon and Cadiz towards Northern Europe. Consequently, Genoese merchant-bankers specialised in offering insurance and brokerage services to European investors in the trade with Spanish America and Brazil.21 Grillo and Lomellino’s entry into the asiento must therefore be understood within this broader process of Genoese investment reallocation. However, their engagement with the asiento reflected varying degrees of interest across its different business opportunities. An analysis of their selective allocation of resources and personal involvement in specific aspects of the contract reveals the underlying strategic importance they attributed to the asiento as a whole.
2 Re-orchestrating the Trade
The organisational model for the asiento introduced in 1662 became a continuous template, used without interruption until mid-eighteenth century by various firms, partnerships and companies that contracted the asiento. While the privileges to each asentista evolved over time and were often expanded with each new asiento, the basic organisational principles established in 1662 remained largely unchanged. Operationally, the asientistas combined their roles as gatekeepers of the slave trade to Spanish America with their responsibilities as suppliers of enslaved Africans. When the asentistas delegated the African and transatlantic legs of the trade to third parties, as Grillo and Lomellino did, they both implicitly and explicitly coordinated diverse business organisations originating from different countries. These partnerships between asientistas and subcontractors managed multiple circuits for redistributing profits derived from the Atlantic world, which were ultimately enjoyed in Europe and sometimes beyond. Like Grillo and Lomellino, subsequent asentistas faced two major organisational challenges: (a) securing reliable suppliers of enslaved Africans with the capacity to transport them to the Caribbean on a regular basis; and (b) managing the importation of enslaved people from non-Spanish Caribbean hubs to Spanish American ports.
2.1 Organising the Asiento from Europe
The framework of the 1662 asiento compelled Grillo and Lomellino to structure their operations in an unprecedented manner. For them, the organisation of the transatlantic slave trade was primarily a European enterprise. Genoese captains frequently sailed to Africa to purchase captives, and the Genoese diaspora maintained a strong presence in the Iberian Atlantic.22 However, the direct management of such a vast operation likely exceeded the capacity of a relatively small firm like Grillo and Lomellino. From the outset of the contract, therefore, the firm sought reliable and strategically positioned European partners capable of securing enslaved Africans in Africa and maintaining sufficient shipping capacity to deliver them to the Caribbean in consistent cycles.
Between 1662 to 1674, Grillo and Lomellino established partnerships with various international suppliers to ensure a steady flow of enslaved Africans to the Caribbean. These suppliers operated through diverse organisational forms, ranging from private partnerships to chartered and joint-stock companies. In September 1662, Grillo and Lomellino signed their first contract with the WIC for the delivery of 1,400 to 2,000 piezas under a single agreement. Soon after, negotiations began with the English Royal Adventurers into Africa (RA), although the activities of English privateers in the Spanish Caribbean led the Crown to undermine any potential agreement between the Genoese and the English company.
Following the initial contract with the WIC, a Dutch joint stock company, Grillo and Lomellino continued to engage with the Dutch market. In April 1663, they secured an agreement with two Dutch private traders, Karel Gijsberti and Volkert Gerritsz. Meanwhile, negotiations with the English resumed in 1664. By March and April of that year, Grillo and Lomellino reached an agreement with the RA for the delivery of 600 to 1,000 piezas initially, followed by an additional 3,000 piezas annually for the duration of their asiento.
The chartered nature of the RA and its compliance with the 1664 contract did not deter Grillo and Lomellino from returning to the Amsterdam market in 1666, where they contracted a group of private traders to secure deliveries of 700, and 400–450 piezas, respectively. However, from that year onwards, the WIC consolidated its dominance in the Dutch market, cracking down on its competitors. As a result, the WIC became the sole legal provider for the asiento. Between 1666 and 1672, at least four additional contracts were signed between Grillo and Lomellino and the WIC, securing the delivery of between 18,800 and 20,000 enslaved Africans.23 In summary, Grillo and Lomellino engaged firms, partnerships, chartered companies, and joint stock enterprises in Amsterdam, London, and Madrid, to transport between 51,950 to 52,500 African captives from West Africa to the Caribbean, all destined for further transport to Spanish America.
The contracts, or more accurately, subcontracts, signed by Grillo and Lomellino with slave-trading enterprises in Amsterdam and London effectively incorporated suppliers from diverse religious backgrounds into the fold of the Spanish Empire. These suppliers operated within business organisations that were inherently transnational, not only because of the international maritime labour forces manning the slaving ships, but also due to the socioeconomic diversity and geographic origins of their investors. In the cases of chartered and joint-stock companies, a significant proportion of investments came from non-English and non-Dutch stakeholders, including members of the Portuguese Nations in Amsterdam and London, particularly in the RA and the WIC.24
Although the contracts between Grillo and Lomellino and the slave suppliers were negotiated and signed in Europe, the payment terms stipulated in the contracts required partial payments in Europe and partial payments in the Caribbean. Furthermore, the contracts specified gender and age ratios of the captives, as well as delivery schedules for their arrival in the Caribbean. Similar to the earlier licensing system under the Portuguese asentistas, these contracts included provisions for potential economic losses due to mortality rates during transport and expenses incurred for the sustenance of captives prior to their embarkation by Grillo and Lomellino’s agents in Curaçao, Jamaica, or Barbados.
2.2 The Trade from Africa
Between 1651 and 1663, the Crown raised no objection to the acquisition of enslaved Africans directly from African markets. During this period, regulations permitted traders supplying the Spanish American markets to control purchases in Africa and deliveries to Spanish America. However, the 1662 asiento curtailed this practice, and Grillo and Lomellino were unable to maintain such control. During negotiations with the Crown, the firm did not articulate a clear position on whether it preferred to import enslaved people directly or indirectly from Africa. In contrast to their Portuguese predecessors, who effectively combined the Portuguese contratos for importing captives from West Africa with asientos for delivering them to Spanish America, the Genoese displayed a pragmatic interest in sourcing as many captives as necessary to fulfil their contract, from whichever suppliers they could engage without specifying supply routes or origins. This ambiguity regarding suppliers and their role in the geographies of the inter-imperial slave trade may have been a deliberate strategy to manipulate the terms of the contract. Ultimately, the final version of the asiento prevented the firm from direct involvement on the West African coast, and it appears that Grillo and Lomellino were not particularly inclined to engage in the African and transatlantic legs of the trade.
An illustrative case occurred on 14 august 1663, when Grillo and Lomellino obtained permission to send the San Juan Bautista to Ardra to purchase slaves.25 However, due to operational delays, likely stemming from lack of interest, the permit remained unused by April 1664, even though the ship was anchored in Cadiz and ready to sail. At that point, the firm petitioned the Crown for permission to redirect the ship to the Caribbean, where it would collect a cargo of enslaved Africans for delivery to Veracruz.26 Despite occasional considerations of sending ships to Africa, Grillo and Lomellino ultimately refrained from doing so.
This decision can be interpreted in at least two ways. Initially, the firm may have been attracted by the potential profits from all legs of the transatlantic slave trade, including the African trade. However, after assuming their role as asentistas, they likely recognize the high risks and costs associated with accessing African markets, compounded by their lack of expertise in navigating these complexities. Alternatively, the permit to trade in Africa may have been a contingency plan to ensure a minimal flow of captives to Spanish America while negotiations with Dutch and English suppliers were still ongoing. Ultimately, the Genoese firm opted to bypass African markets altogether, focusing instead on intra-Caribbean exchanges. This approach, which involved subcontractors delivering captives from the Caribbean to Spanish American ports under the firm’s name, demonstrates that their primary objectives lay in the intra-Caribbean trade rather than the broader trans-imperial transatlantic trade.
2.3 The American Networks and the Colonial Markets
In contrast to their limited involvement in the African trade and the Middle Passage, Grillo and Lomellino sought to tightly control the inter-imperial Caribbean slave trade and the distribution of captives in Spanish America. This enhanced control over the Caribbean trade increased opportunities to maximise profits through diverse channels. The legal importation of enslaved Africans into Spanish American markets from the wider Caribbean was frequently accompanied by tax evasion, creating a perpetual cat-and-mouse game with royal officials. According to official records, Grillo and Lomellino transported approximately 21,234 captives from the Dutch and English Caribbean to Spanish America over an eleven-year period. This accounted for about 70% of the quota stipulated in their original contract. Furthermore, the firm used the trans-Caribbean trade as a cover for smuggling Spanish American commodities and European goods, leveraging the guise of the slave trade to facilitate illicit exchanges.
To manage their business in the Caribbean, encompassing the redistribution of enslaved Africans, tax evasion, and the smuggling of Spanish American commodities and European goods, Grillo and Lomellino deployed a network of official factors. These factors acted as key intermediaries connecting Curaçao, Jamaica, and Barbados with the three ports where the asiento was authorised to operate: Cartagena, Portobelo, and Veracruz. Cartagena and Veracruz regained their role as exclusive ports for channeling enslaved Africans into the regional Spanish American markets, though neither port ever recaptured the prominence they had achieved during the Portuguese asientos. Instead, Portobelo emerged as the primary gateway for the introduction of African captives to Spanish America in the decades that followed.27
In each of these ports, Grillo and Lomellino were entitled to appoint three representatives of their firm, who were permitted to travel to the Dutch and English Caribbean islands. As the number of Spanish American ports authorised to receive enslaved individuals expanded over time, the firm’s network of factors grew to include locations such as Caracas, San Juan de Puerto Rico and Havana.
From an inter-imperial perspective, these factors coordinated voyages between the Dutch and English slave-supplying hubs in the Caribbean – primarily Curaçao, Jamaica, and Barbados – and Spanish American ports. Curaçao supplied 89,5% of the enslaved Africans, while the remaining captives were dispatched by the English from Barbados (5,5%) and Jamaica (5%).28 These voyages were undertaken by fleets of five to seven ships hired by Grillo and Lomellino, while others were chartered from across Europe.29
In the intra-Caribbean transport, careful timing was critical to ensure that the enslaved were ready for transport from Curaçao and Jamaica. This aspect was pre-emptively addressed in the contracts between Grillo and Lomellino and their subcontractors, signed in Europe. To comply with contractual agreements, the factors also needed to manage substantial stocks of silver, whether in ingots or minted pesos, and commodities for payment and barter. The firm leveraged its access to regional markets for cochineal, cocoa, and indigo, commodities in high demand in European and Asian markets, the latter serviced by the Dutch and the English East India companies (VOC and EIC, respectively).
To execute these tasks, Grillo and Lomellino incorporated into their networks individuals with the expertise and experience necessary to operate within inter-imperial and Spanish American markets. The case of Francisco Hermans is illustrative. Born in Antwerp, Hermans possessed linguistic skills that proved invaluable in maintaining and strengthening relations with Dutch authorities and WIC shipmasters in Curaçao. After passing the scrutiny of the Consejo de Indias and demonstrating his status as a Catholic subject of the Spanish Crown, Hermans formally joined the asiento administration in May 1669.30 With extensive experienced in Atlantic trade and smuggling, he brought valuable expertise to the firm. For example, in 1659 Hermans transported wine from the Canary Islands to Guinea, where he exchanged it for enslaved Africans, whom he then delivered to Buenos Aires. His associates in this venture included Benito and Manuel Almeida, Portuguese vecinos of Sanlúcar de Barrameda, and Mateo Domínguez from the Canary Islands.31 By December 1669, Hermans was already in Cartagena, receiving the San Fortunato on her return from Curaçao, carrying 309 enslaved Africans and a significant quantity of contraband, including Asian cinnamon and black pepper, European cloth, and Italian silk.32
Similarly, Andalusians, Castilians, Creole, and Genoese individuals also joined the ranks of factors in the asiento networks. The factors oversaw the flow of enslaved Africans into three main ports, which concentrated 86,2% of the firm’s documented trade. Approximately 11,400 captives were delivered to Portobelo, 4,800 to Cartagena, and 2,100 to Veracruz. The remaining 13,7% of enslaved individuals were disembarked at other ports, including Caracas, Cumaná, La Guaira, San Juan de Puerto Rico, Santiago de Cuba, and Santo Domingo.33
Once the captives were introduced onto Spanish American soil, a new phase of the asiento began. While some enslaved individuals were sold at their ports of arrival, the majority were transported to other destinations for resale. For instance, from Portobelo, captives were transported across the Isthmus of Panama to Panama City. There, part of the group was sold, but most continued their journey to El Callao in Peru. After arrival in El Callao, the survivors were transported to Lima, where they were finally sold. Similarly, Veracruz served as both a port of entry and a transit hub. In September 1669, the San Vicente arrived from Curaçao with 501 enslaved. Approximately 200 were sold in Veracruz, while the remainder awaited redistribution. By December of that same year, one of the firm’s factor oversaw the inland passage of these men, women and children, from Veracruz to Mexico City.34
The distribution of enslaved individuals required extensive logistical knowledge of routes and markets, which the factors alone did not possess. These operations also involved smuggling European and Asian commodities into inland markets and exporting Spanish American commodities in return. Reliable shipmasters and skilled crews were essential for navigating imperial borders in the Caribbean, while similar expertise was required to manage the Pacific coast routes from Panama to Peru. Surgeons, cooks, and guards were vital for ensuring the survival of the enslaved during the harsh marches through the inland passages, while muleteers and shipowners facilitated the transport of both enslaved individuals and contraband commodities.
Grillo and Lomellino engaged in fraud related to the importation of the enslaved and large-scale contraband. Cooperation with local authorities was therefore essential. The firm’s factors played a crucial role in forging the necessary alliances at a local level. For example, Italian factors such as Giustiniano Giustiniani or Pedro Matias Cavalieri became deeply integrated in local society by marrying local women of high social standing and spending most of their lives in Spanish America.35 The success of the ‘Genoese’ asiento heavily relied on the competence and local embeddedness of these factors, whether in dealing with local authorities, managing cross-American and Pacific transportation networks, or navigating local market for enslaved individuals and commodities.
In addition to mediating the interest of the asentista and managing transactions related to the asiento, the factors were also responsible for enforcing its clauses – a challenging and often hazardous task. As might be expected, the arrival of these factors in Spanish America was fraught with difficulties. While many local actors benefited from collaborating with the asiento, others did not. The asiento was partially intended to displace, or at least to compete with, the thriving merchant networks that operated within unofficial Spanish American markets, many of which maintained close ties with local authorities. A significant source of local opposition to the asiento arose from these authorities, who had previously profited from the unofficial slave trade. The Genoese firm frequently complained to the Consejo de Indias about the lack of support their agents received from Spanish American royal officials dispersed across the Caribbean.
It is difficult to precisely assess the extent, nature, and location of challenges to the asiento managed by Grillo and Lomellino. Nonetheless, the various lawsuits the firm initiated against smugglers, the numerous seizure operations conducted by their factors, and the reports submitted to the Consejo de Indias all serve as indicators of resistance to the asiento. At the same time, complaints filed by the firm provide valuable insights into the organisation of illegal trade. For instance, in January 1663, Domenico Grillo reported that in August 1662, the San Vicente and the Águila Negra called at Curaçao, aiming to transport approximately 250 piezas to Lima, Peru. Grillo claimed that the San Vicente was a Spanish ship, though its captain and crew were Portuguese, and included merchants from Cartagena. Similarly, the Águila Negra, a Dutch ship under contract to Lima-based merchants,36 also carried merchants from Cartagena and Seville.
The investors behind the Águila Negra and the San Vicente were likely similar to individuals such as Gaspar Alfonso, a Panama-based merchant who specialised in shipping enslaved Africans from Cartagena to Portobelo during the 1650s. Alfonso was apprehended in 1664 by one of Grillo and Lomellino’s factors, alongside local authorities in Portobelo, while attempting to disembark a cargo of fifty-nine piezas.37 In cases like Alfonso’s, Grillo and Lomellino occasionally incorporated such local smugglers into the asiento. However, it remains unclear what criteria governed the inclusion of some and the exclusion of others. Regardless, it becomes evident that firms operating the asiento in a monopolistic fashion could not do so effectively without the tacit support and vested cooperation of local officials and merchant elites.
Grillo and Lomellino’s factors also faced opposition from other quarters, notably local tax collectors. These individuals were typically prominent businessmen embedded within networks of alliances that connected them with royal officials and influential members of the colonial elite. As previously noted, one of the innovations of the 1662 asiento was the taxation structure it introduced: taxes on the slave trade were abolished, and all fiscal revenues were directly channelled to the royal treasury in Madrid. Implementing this change was contentious, as it disrupted local tax collection systems, diminished revenues, and undermined the social capital of those who held the rights to collect taxes locally. When Grillo and Lomellino’s factors refused to pay taxes claimed by local tax farmers, disputes arose in cities such as Veracruz and Panama. The Crown and the Consejo de Indias maintained a firm stance on upholding the asiento privileges and tax exemptions, but local tax farmers escalated the conflict by petitioning the Consejo de Hacienda for revisions to their tax-farming contracts and discounts on previously agreed sums, straining relations between the Consejo de Hacienda and the Consejo de Indias.38
One of the most valuable tools available to Grillo and Lomellino for defending their interests overseas was the figure of the juez conservador (notorised magistrate). The jueces conservadores oversaw the enforcement of the asiento’s privileges and were the only officials authorised to intervene in cases where the asiento’s clauses were breached or challenged. However, the ability of jueces conservadores to implement their decisions was limited, as they were heavily reliant on local institutions and authorities. Nonetheless, the jurisdictional powers granted to them insulated asiento-related matters from interference by other local authorities or courts. The critical importance of the jueces conservadores was well recognised by detractors of the asiento. For instance, the guild of transatlantic merchants of Seville (consulado) attributed the Genoese firm’s power to its dual monopoly on the importation of enslaved Africans and jurisdiction over all matters related to the asiento.39 This concentration of authority represented a significant departure from the Portuguese asientos, establishing a new jurisdictional framework that would sustain the trade into the eighteenth century.
During the eleven years of the ‘Genoese’ asiento, Grillo and Lomellino proposed the appointment of at least forty-one jueces conservadores. Thirty-seven were assigned to Spanish America, spanning locations from México City to Buenos Aires, while the remaining four served in Castile. Notably, these appointments were not limited to the ports officially designated for the asiento trade, but extended to regions where Grillo and Lomellino alleged that their monopoly was being violated. This strategy allowed the firm to enforce its jurisdiction across all Spanish American constituencies.
The appointments were made in Madrid, where Grillo and Lomellino submitted their nominees to the Consejo de Indias for approval. The candidates were selected for their technical knowledge of conflict resolution, legal procedures, and litigation. These candidates fell into two categories. The first comprised individuals drawn from the local communities where they would serve, chosen for their familiarity with local smuggling networks, understanding of regional power dynamics, and ability to identify potential collaborators. Many of these individuals held positions as governors or royal officials, which provided them with the executive authority necessary to enforce their decisions as juez conservador. However, integrating these individuals into the asiento’s sphere of influence often required dislodging them from local interests that conflicted with the monopoly.
The second group of jueces conservadores comprised men recently appointed by the King to serve as high-ranking royal officials in Spanish America. Through their networks of contacts at court and in various councils, Grillo and Lomellino were able to gather information about these new appointees. They shortlisted some of these individuals and subsequently proposed their names as jueces conservadores of the asiento. The primary advantage of integrating this group of newly appointed colonial officials into the asiento was the opportunity to co-opt them while they were still in Spain, before their departure to the Americas. Equally significant was the fact that these men were not yet embedded within local elites, making them more amenable to overseeing the asiento in their respective jurisdictions.40
The appointment of jueces conservadores by Grillo and Lomellino does not necessarily imply that these individuals always acted in the firm’s interest or supported its factors in Spanish America. While some jueces conservadores benefitted from aligning themselves with Grillo and Lomellino, others prioritised their personal gain or even opposed the firm. For instance, Don Diego Ortíz de Largacha, governor and alférez mayor (lieutenant major) of Veracruz and juez conservador of the asiento, became one of the most influential figures in Veracruz in 1667. His wealth included real estate, livestock, jewelry, and African slaves.41 In 1665, Ortíz de Largacha had supported the asiento factors in a contentious lawsuit against local tax farmers, which also implicated other high-ranking officials in Veracruz.42 Despite the risk of alienating his peers, Ortíz de Largacha’s ruling upheld the asiento’s privileges, leading to a significant financial loss for the tax farmers. Collaboration with Grillo and Lomellino’s factors allowed him to further enhance his personal fortune.
In contrast, Andrés Robles, the juez conservador in Buenos Aires, also amassed personal wealth through the asiento, but at the expense of Grillo and Lomellino. Robles never remitted the 60,000 pesos or the cloth seized from two slave ships attempting to call at Buenos Aires to smuggle goods, keeping the profits for himself.43
Some jueces conservadores served the private interests of the asentistas, while others prioritised their own wealth or aligned with local opponents of the asiento. However, their role was not necessarily a binary choice between these sides. In 1672, Grillo and Lomellino’s factors in Lima expressed outrage at the decisions made by Don Álvaro de Ocampo, the juez conservador in the region. Ocampo adhered strictly to his judicial responsibilities, refusing to take sides in disputes involving the asiento factors, the Viceroy of Peru, and the Lima merchant guild. His impartiality displeased the factors, who resented his refusal to accept a salary for fulfilling his duties as magistrate.
3 Conclusion
Following a decade during which the official African slave trade to Spanish America was effectively suspended by the Crown and another ten years during which it operated beyond its control, the asiento of Grillo and Lomellino reorganised the foundations of the contract and the trade itself. Institutionally, the ‘Genoese’ asiento marked a decisive break from the ‘Portuguese’ asiento system. From 1662 until the 1740s, firms and companies engaged in the asiento de negros operated as monopolistic players within an exclusive and differentiated jurisdictional space in the Spanish Empire’s framework. The fiscal system governing the trade in enslaved Africans was also transformed: instead of revenues being collected locally in Spanish America, all income was now channelled directly to the royal treasury in Madrid, to the detriment of Spanish American town councils.
The geography of the trade also shifted. The primacy of Cartagena and Veracruz as leading slaving hubs declined, and official slave trade operations gradually expanded to multiple ports. The trans-imperial intra-Caribbean routes became the primary source of enslaved Africans for Spanish America. Consequently, the business of slavery grew increasingly fragmented and specialised, with transatlantic operators and intra-Caribbean slave traders flourishing, at the devastating cost of the lives and suffering of enslaved Africans.44
The profile of merchants involved in the trade also evolved significantly compared to the pre-1640 period. Although Grillo and Lomellino were the public faces of the asiento, it is incorrect to characterise the post-1662 asiento as an exclusive Genoese enterprise. Under the Genoese firm’s aegis, Dutch and English, previously excluded from Spanish America due to their religious beliefs or hostile relations with Spain, entered the trade and aligned their interests with the asentistas. These newcomers were often companies that emerged from transnational investment networks.
The post-1662 asiento also opened the door to further internationalisation of the slave trade to Spanish America. While the RA and the WIC were prominent newcomers, Italians, Spanish, and Creoles continued to participate and benefit from the new asiento system. Over time, Portuguese actors also re-entered the trade, underscoring the broad and diverse participation in this evolving system.
Bethencourt, Strangers Within. Vila Vilar, “La sublevación de Portugal”, 171–192.
Alfonso W. Quiroz, “The Expropiation of Portuguese New Christians in Spanish America, 1635–1649,” Ibero-Amerikanisches Archiv 11, no. 4 (1985), 407–465; Bernardo López Belinchón, Honra, libertad y hacienda: hombres de negocios y judíos sefardíes (Alcalá de Henares: Instituto Internacional de Estudios Sefardíes y Andalusíes – Universidad de Alcalá, 2001); Newson and Minchin, From Capture to Sale.
Tatiana Seijas and Pablo M. Sierra, “The Persistence of the Slave Market in Seventeenth-Century Central Mexico,” Slavery & Abolition 37, no. 2 (2016), 307–333; Alejandro García-Montón, “The Rise of Portobelo and the Transformation of the Spanish American Slave Trade, 1640s–1730s: Transimperial Connections and Intra-American Shipping,” Hispanic American Historical Review 99, no. 3 (2019), 407–410.
Klooster, Illicit Riches, 41–43, 59–61, 65–67, 73–74, 105–109; Cátia Antunes and Filipa Ribeiro da Silva, “Amsterdam Merchants in the Slave Trade and African Commerce, 1580s-1670s,” Tijdschrift Voor Sociale En Economische Geschiedenis 9, no. 4 (2012), 22–24.
Moutoukias, Contrabando y control; Silva, Dutch and Portuguese; Shultz, “‘The Kingdom of Angola”, 424–444.
Klooster, The Dutch Moment, 56.
Moutoukias, Contrabando y control, 105–11; Klooster, Illicit Riches, 41–43, 52–56.
Klooster, The Dutch Moment, 81–83 and 160–164; Lou H. Roper, Advancing Empire: English Interests and Overseas Expansion, 1613–1688 (New York: Cambridge University Press, 2017), 62–70 and 71–85.
Klooster, The Dutch Moment, 163; Roper, Advancing Empire, 79.
https://www.slavevoyages.org/voyages/cQoaSHfP, (accessed 29 March 2024)
Vila Vilar, “La sublevación de Portugal,” 180.; https://www.slavevoyages.org/voyages/mtcmTkRg (accessed 29 March 2024).
Archivo General de Indias (henceforth AGI), Indiferente General (Henceforth IG), Leg. 2797, s.f., 1654. Licenses for Juan Bautista Pluma.
AGI, Escribanía, Leg. 6-A, s.f. 1657; https://www.slavevoyages.org/, voyage identification number 41463.
Rafael Valladares, Banqueros y vasallos: Felipe IV y el medio general (1630–1670) (Cuenca: Universidad de Castilla La Mancha, 2002); Xabier Lamikiz, “Fiscalidad y Fraude En La Reactivación de La Carrera de Indias, 1660–1700,” in Dinero Del Rey: Finanzas y Cambio Fiscal En La Monarquía Hispánica, Siglos XVI–XVII, edited by Ramón Lanza García (Granada: Comares, 2021).
Nuala Zahedieh, “The Merchants of Port Royal, Jamaica, and the Spanish Contraband Trade, 1655–1692,” The William and Mary Quarterly 43, no. 4 (1986), 570–593; Wim Klooster, “Curaçao and the Caribbean,” in Riches from Atlantic Commerce: Dutch Transatlantic Trade and Shipping, 1585–1817, edited by Johannes Postma and Victor Enthoven (Leiden and Boston: Brill, 2003), 203–218; Han Jordaan, “The Curaçao Slave Market. From the Asiento Trade to Free Trade, 1700–1730,” in Riches from Atlantic Commerce: Dutch Transatlantic Trade and Shipping, 1585–1817, edited by Johannes Postma and Victor Enthoven (Leiden and Boston: Brill, 2003), 219–57.
AGI, Contaduría, Leg. 562, nº 1, fols. 1r-8r, 23-VII-1663.
Fernando Serrano Mangas, Los Galeones de la Carrera de Indias 1650–1700 (Sevilla: EEHA-CSIC, 1985), 98–105.
Carlos Álvarez-Nogal, El crédito de la monarquía hispánica en el reinado de Felipe IV (Valladolid: Junta de Castilla y León, 1997).
Carmen Sanz Ayán, Los banqueros de Carlos II (Valladolid: Universidad de Valladolid, 1988).
Giuseppe Felloni, Gli investimenti finanziari genovesi in Europa tra il Seicento e la Restaurazione (Milano: A. Giuffrè, 1971).
María Guadalupe Carrasco Gonzalez, Comerciantes y casas de negocios en Cádiz, 1650–1700, Cádiz, Universidad de Cádiz, 1997; Leonor Freire Costa, “Genoveses nas rotas do açucar: A intromissao em exclusivos coloniais portugueses (c. 1650)”, in Génova y la Monarquía Hispánica (1528–1713), vol. 2, edited by edited by Manuel Herrero Sánchez, Yasmina Rocío Ben Yessef Garfia, Carlo Bitossi and Dino Puncuh (Genova, Società Ligure di Storia Patria, 2011), 915–932; Nunziatella Alessandrini y Antonella Viola, “Genovesi e fiorentini in Portogallo: Reti commerciali e strategie politico-diplomatiche (1650–1700)”, Mediterranea. Ricerche storiche 28 (2013), 295–322.
Maria Luísa Esteves, “Para o estudo do tráfico de escravos de Angola (1640–1668),” Studia 50 (1991), 29–60; Maria Luísa Esteves, “Para o estudo das relações comerciais de Angola com as Índias de Castela e Génova no período da Restauração (1640–1668),” Studia 51 (1992), 29–60.
See, respectively: AGI, Contaduría, Leg. 262, ramo 1, fols. 1r-6r; AGI, Contaduría, Leg. 262, ramo 1, fols. 7r-11r; AGI, IG, Leg. 2830, fols. 378r-85r; AHPM, 7356 Muñoz, s.f., 9-IV-1664; AGI, Contaduría, Leg. 262, ramo 8, fols. 30r-4v; AGI, Contaduría, Leg. 262, ramo 8, fols. 35r-9r; AGI, Contaduría, Leg. 262, ramo 8, fols. 42r-9v; Goslinga, The Dutch in the Caribbean, 514–17; GAA, NA, 3204, fols. 422r- 8v; AGI, IG, Leg. 2833, s.f. 30-X-1672.
Herbert I. Bloom, The Economic Activities of the Jews of Amsterdam in the seventeenth and eighteenth centuries (Williamsport: The Bayard Press, 1937), 39.
AGI, IG, Leg. 2834, s.f. 9-IX-1663.
AGI, IG, Leg. 2834, s.f., 4-IV-1664.
García-Montón, “The Rise of Portobelo.”
Marisa Vega Franco, El tráfico de esclavos con América (asientos de Grillo y Lomelín, 1663–1674) (Sevilla: EEHA-CSIC, 1984), 186–187, 194–202.
Vega Franco, El trafico de esclavos, 101–125.
AGI, IG, Leg. 2834, s.f., 23-III-1669 and 29-V-1669; AGI, Contratación, Leg. 5436, n.º 65, 11-V-1669.
García Fuentes, El comercio español, 144 and 157.
AGI, Contaduria, Leg. 1433, n.º 3.
Vega Franco, El tráfico de esclavos, 186–187, 194–202.
Sierra Silva, “Portuguese ‘Encomenderos’”, 239–241.
Alejandro García Montón, “Esclavistas italianos, linajes Navarros y nueva nobleza Borbónica: Justiniano Justiniani, el Istmo de Panamá y el Marquesado de Peñaflorida (1630–1714),” in Identità Nobiliare Tra Monarchia Ispanica e Italia. Lignaggi, Potere e Istituzioni (Secoli XVI–XVIII), edited by Carmen Sanz Ayán et al. (Roma: Edizioni di storia e letteratura, 2019), 55–69.
AGI, IG, Leg. 2834, s.f., 14-I-1663.
AGI, Panamá, Leg. 24, R.2, N.54 ll-p.
AGI, Escribanía, Leg. 292-A, Lawsuit between alcabala tax collectors and Grillo and Lomellino, 1665.
AGI, IG, Leg. 2834, s.f., 19-III-1669.
Alejandro García-Montón, “Corona, Hombres de Negocios y Jueces Conservadores. Un Acercamiento En Escala Transatlántica (s. XVII),” Jerónimo Zurita 90 (2015), 75–112.
Michel Bertrand, Grandeza y miseria del oficio: Los oficiales de la Real Hacienda de la Nueva España, siglos XVII y XVIII (México D.F.: Fondo de Cultura Economica, 2013), 460–61.
AGI, Escribanía, Leg. 292-A Lawsuit between alcabala tax collectors and Grillo and Lomellino, 1665.
AGI, IG, Leg. 2835, s.f., 27-V-1673; AGI, Buenos Aires, Leg. 3, Lib. 9, fols. 237v-40v.
Gregory E. O’Malley, Final Passages: The Intercolonial Slave Trade of British America, 1619–1807 (Chapel Hill: University of North Carolina Press, 2014); Borucki, Eltis and Wheat, “Atlantic History”, 433–461.