This paper introduces the city of Mardin and the most influential leaders of the Artuqid dynasty, their religious and political activities, as well as their stance against the Crusaders. The paper focuses on the Christian religious life, specifically Christianity, showing their most distinguished Christian sects, leaders, places of worship, and their status among the Artuqids. As for the Muslims, the Matruridi Ash'ari Sunni doctrine was the prevailing doctrine in Mardin and the area around it. Salah al-Din himself was brought up by the Ash'ari doctrine which he taught to his young sons. Mardin was not far from the Ismaili Batiniyya influence because of their presence in Iran and Persia, and also the Hamdanid Shia of Aleppo, but they did not have a great influence on the religious life in Mardin. The Artuqids had a great role in facing the Crusaders, but this was not enough to deter them, and this explains why Salah al-Din extended his influence on Mardin and its environs to unify these areas towards the liberation of Bayt al-Maqdis.