The earliest fortress of Nimrud/Subayba was built around 1228 by al-Aziz Uthman, the Ayyubid Muslim ruler of the nearby town of Banias. Over the next five decades the fort was twice restored and expanded in anticipation of Crusader invasions into the upper Huleh Valley that never materialized. The final renovations were undertaken by the Mamluk sultan Baybars (1260–1277).