After the decay of the Fatimid political system in the 1160s , the Zengid ruler NÅ `` r ad-D Ä `` n had his general , Shirkuh , seize Egypt from the vizier Shawar in 1169 . After the decay of the Fatimid political system in the 1160s , the Zengid ruler NÅ `` r ad-D Ä `` n had his general Shirkuh , seize Egypt from the vizier Shawar in 1169 .