In 1142, within the ancient walled city of Kerak, Crusader King Baldwin I built a fortified castle, which was acquired in 1161 by Renaud de Chatillon, one of the most famous and cruel of the Crusaders. The castle was one in a chain from Turkey to Aqaba, and was well placed over the Kings' Highway, allowing Chatillion to control the lucrative trade route.

The Crusaders lost the area in 1189 to Salah ad-Din Yusuf ibnAyyub, the great Muslim who began the lengthy Ayyubid sultanate which would eventually rule much of the Mideast for 500 years. Saladin assumed the Kerak castle as his own as he planned the final assault on Jerusalem. He personally beheaded Chatillon for breaking a treaty and raiding one of his caravans.

The design is a typical example of early European fortresses integrated into the Mideast. Quickly built, the construction is crude by the standards of the day, with little of artistic merit. But with massive Romanesque-style stone vaults, numerous corridors, and strong doorways, it reflects the growing European militarism that would ultimately dominate the world.