Currencies, Land Areas and Weights and Measures
Currencies of Account
In an economic study over a long period of time and covering several separate and distinct territories (Aragon, Catalonia, Valencia and Roussillon), the issue of comparability of monetary sums inevitably arises. It is always important to bear in mind the distinction between money of account, in which contracts were denominated, and specific coins, whose actual silver or gold content often did not correspond with the officially sanctioned rates of conversion.
Transactions studied in Barcelona and Girona are denominated either in sous of Barcelona (variously issued as doblenc, terno and quaterno, all with different silver contents); dineros; libras (the libra normally worth 20s. and dinero normally 1/12 s. but varying as artificial exchange rates were established by the crown, on occasion down to 1/16 s.); gold morabatins (although various different morabatin coins circulated at different times, these are generally specified as alfonsine gold morabatins, known in Castile as the maravedi and also referred to as aurea and, in Hebrew sources, gold dinars). In Aragon, the main currency of account was the sueldo of Jaca, established as mint in 1077; in Roussillon, the Melgorien sous (or sous of Melgueil). In Valencia, most transactions are denominated in Valencian sous. The florin, used for trading from the fourteenth century onwards, is found in our studies only from 1375. The exchange rates varied widely over time and between individual transactions and no precise equivalences can be given. However, the broad equivalences are set out in Table 1 and discussed in full in Appendix 1.
Measures of Land Area, Weights and Measures
Plots of land are measured in a number of different units, varying according to the type of plot but also with substantial local variations. Table 2 gives the best estimates of the modern equivalences. Appendix 2 lists the sources and possible alternative conversion ratios for land areas, as well as measures of weight and volume of wheat and weight of grapes.