trade was one of the most single important generators of revenue for the crusader states
it was equally important for muslim held cities near outremer, which included damascus and aleppo, to have a means to trade their goods with byzantium and western europe
this means was provided by the ports of acre and tyre which were home to communities of both christians and muslims
examples
in both tyre and acre there were mosques provided for muslims to worship in - evidence that a converted mosque was shared by both christians and muslims at Acre
royal protection was granted by baldwin III to Ibn Izz ad’Din (a muslim from tyre) to trade with eygpt
in 1180, Ibn Jubayr said that 2 Muslim traders who dominated business on the coast of outremer were from north africa and lived in Damascus
taxes imposed on traders:
sugar
shoes
cardamom
any product that was exported to non Christians had an additional 1 karouble duty
these indicate that outremer was a vibrant trading community that relied upon connections from well beyond its christian settlements