Under the Comnenian dynasty (1081–1185), Byzantium staged a remarkable recovery. In 1090–91, the nomadic Pechenegs reached the walls of Constantinople, where Emperor Alexius I with the aid of the Kipchaks annihilated their army. In response to a call for aid from Alexius, the First Crusade assembled at Constantinople in 1096, but declining to put itself under Byzantine command set out for Jerusalem on its own account. John II built the monastery of the Pantocrator (Almighty) with a hospital for the poor of 50 beds.