Naval power from the Latins in the East, at times with assistance from the French Crown and the papacy, came to form the forefront of crusading against the Turks in the Aegean, culminating in the naval leagues of the 1330s and 1340s. But the merchants and mariners who made up the Aegean fleets were not just motivated by a desire to defend the faith from the infidel; their interests were also inseparably intertwined with the web of cross-cultural commerce in the eastern Mediterranean. This often resulted in a dilemma for the participating merchant states, as they attempted to balance peaceful commercial relations in the East with the need to defend their lands from Muslim aggression, and the inevitable disruption to trade that this caused. The commercial priorities of these merchant crusaders were far removed from those of the traditional crusading powers of western Europe and consequently posed new problems for the Church, which had to re-orient its policies to accommodate the new political-economic situation in the Aegean region, whilst not being seen to be completely relaxing its policy towards trading with infidel. As a result of this, trade licences, such as that granted to Garin of Châteauneuf above became a prominent feature of papal crusading policy.

Initial Conflicts between Commerce and Crusade in the Aegean

During the first half of the fourteenth century successive popes promulgated a ‘total embargo’, which theoretically forbade trade with the entire Muslim world. This prohibition was then reiterated by the authorities of the maritime republics, who provided detailed lists of the penalties for those who broke the papal decrees, even though in reality these reiterations were not always carried out in full. The trade ban had a mixed impact on Mediterranean commerce: it did not result in the complete isolation of Muslim lands from Latin merchants, as many private individuals still broke the embargo, but it was sufficient to force the re-direction of much Christian trade from Egypt to lands further north; a factor which was accentuated by the loss of the Holy Land and the expansion of Latin colonies in the Aegean and the Black Sea.