The crusaders may have been aware of the new divisions among the Ayyubids; al-Kamil had occupied Damascus in 1238 but had died soon afterwards, and his territory was inherited by his family. His sons al-Adil abu Bakr and as-Salih Ayyub inherited Egypt and Damascus. Ayyub marched on Cairo in an attempt to drive out al-Adil, but during his absence al-Kamil's brother as-Salih Isma'il took over Damascus, and Ayyub was taken prisoner by an-Nasir Dawud. The crusaders, meanwhile, marched to Ascalon. Along the way, Walter of Brienne captured livestock intended to resupply Damascus, as the Ayyubids had probably learned of the crusaders' plans to attack it. The victory was short-lived, however, as the crusaders were then defeated by the Egyptian army at Gaza in November 1239. Henry II, Count of Bar was killed and Amaury of Montfort captured. The crusaders returned to Acre, possibly because the native barons of the kingdom were suspicious of Filangieri in Tyre. Dawud took advantage of the Ayyubid victory to recapture Jerusalem in December, the ten-year truce having expired.