Iberia is the peninsula where Christianity, Islam and Judaism occupied the same ground for the longest continuous period anywhere in Europe. Muslim armies crossed from North Africa in 711 and within a decade held most of the peninsula; the emirate and then caliphate of Cordoba made that city one of the largest and most learned in the western world by the tenth century. Christian kingdoms in the north pushed south over the following five hundred years, and the last Muslim state, the emirate of Granada, fell in 1492.
The word convivencia is used for the arrangement that held in between, and it is contested. It named a legal order rather than a friendship: Jews and Christians under Muslim rule, and later Muslims and Jews under Christian rule, were tolerated subordinate communities with their own courts and their own taxes, and the arrangement produced both sustained intellectual exchange and periodic violence. Both the philosophy of Maimonides, written in Arabic by a Jew who then had to leave, and the Almohad persecution that made him leave belong to the same century.
What the contact produced is not in dispute. Arabic and Hebrew philosophical vocabulary entered Latin through this peninsula, Jewish mysticism took its classical form here, and Sufi, Jewish and Christian mystical writing in the region borrowed vocabulary from one another in ways scholars are still tracing.