Islam
Nuradin and Egypt
The Fatimids in Egypt were falling apart in the 1150s. A series of seemingly endless murders within the palace had put one caliph after another in place, none of whom actually ruled (most were mere boys); instead, Egypt was run by its viziers, who were the instigators (and victims) of most of the murdering.
In December 1162, the latest in the parade of usurpers was Shawar, governor of Upper Egypt. He was driven out of power in 1163 by his own chamberlain, Dhirgham. By this time, the plotting between the various factions was so thick that Dhirgham was putting to death anyone who even looked suspicious. The result of months of this left the Egyptian army with few of its experienced officers still alive.
King Amalric tried to go fishing in these waters in 1163, and while he was gone, Nuradin attacked Krak. Count Raymond called for help. Bohemond III of Antioch responded, accompanied by Byzantine troops under Constantine Coloman. They surprised Nuradin in camp and dealt him a sharp defeat. At this point, Shawar appeared to appeal to Nuradin for help in Egypt. After some delay, he sent his most trusted general, Shirkuh, along with a large army. In his company was the general's nephew, Salah ed-Din. They were immediately victorious. Dhirgham was killed and Shawar re-instated as vizier.
Shawar now refused to honor his agreement with Nuradin and ordered Shirkuh to leave. Instead, Shirkuh seized Bilbeis. Worried now, Shawar sent to Amalric for help. Together they besieged Shirkuh for three months.