The Ayyubid dynasty, also known as the Ayyubid Sultanate, was a Sunni Muslim Kurdish dynasty that founded the medieval Sultanate of Egypt, which was established by Saladin in 1171, following his abolition of the Fatimid Caliphate. Saladin had originally served the Zengid ruler Nur al-Din, leading the latter's army against the Crusaders in Fatimid Egypt, where he was made vizier. Following the death of his Zengid suzerain Nur al-Din in 1174, Saladin was proclaimed as the first Sultan of Egypt by the Abbasid Caliphate, and rapidly expanded the new sultanate beyond Egypt to encompass most of Syria, in addition to Hejaz, Yemen, northern Nubia, Tripolitania and Upper Mesopotamia. Saladin's military campaigns set the general borders and sphere of influence of the sultanate of Egypt for the almost 350 years of its existence. Most of the Crusader states fell to Saladin after his victory at the Battle of Hattin in 1187, but the Crusaders reconquered the Syrian coastlands in the 1190s.