JL;DR

In medieval Ashkenaz, Jewish communities played a significant role in commerce and economic life, navigating both opportunities and restrictions imposed by Christian rulers. This careful balancing act involved engaging in trade, money lending, and other economic activities that were often limited or shunned by the surrounding Christian populace. Despite periodic tensions and restrictions, Jewish merchants and financiers contributed significantly to the economic development of their regions. The adaptation to these roles was influenced by religious, social, and legal frameworks of the time, further complicating their status within medieval European society.