The local Byzantine commander, Marianos Argyros, visited the caliphal court and arranged for truce, but it was soon broken and warfare resumed. In spring 957, Ammar crossed from Sicily to Calabria, but the Fatimids themselves suffered heavy losses in a storm. Another effort by Argyros to renew the truce in autumn failed, and in the next year, Ammar and Hasan defeated his forces in Sicily; but soon after, as the Fatimid fleet was returning from Calabria to Sicily, it was again wrecked in a storm off Palermo, in which Ammar perished (on 24 September 958, according to the Cambridge Chronicle; al-Maqrizi places these events two years earlier).