Islam

Islam is a monothestic religion based on the worship of Allah (Arabic for, simply, "God") as revealed by the teachings 6th Century prophet Mohammed. The writings of Mohammed were collected in the Qu'ran (alternatively spelled Koran) and form the basis of this faith.

A follower of Islam is called a Muslim.

In period, Muslims were regarded as the enemies of Christian Europe, and reviled accordingly. The Crusades were a series of vicious wars, primarily against Muslims, to "liberate" the city of Jerusalem and the Holy Land from Muslim control.

Your SCA Persona is a Muslim

Quite likely if you have a Middle Eastern or Islamic persona. Contact between Christian Europe and the Muslim middle east was extensive, owing to the Crusades, the Christian practice of pilgrimage, and trade.