In the autumn of 1169 Manuel sent a joint expedition with Amalric to Egypt: a Byzantine army and a naval force of 20 large warships, 150 galleys, and 60 transports joined forces with Amalric at Ascalon. The joined forces of Manuel and Amalric laid siege to Damietta on 27 October 1169, but the siege was unsuccessful due to the failure of the Crusaders and the Byzantines to co-operate fully. When the rains came, both the Latin army and the Byzantine fleet returned home, although half of the Byzantine fleet was lost in a sudden storm.