During the reconquest of Roger I's "Kingdom of Africa" by the Muslims (1159), Peter led 160 ships in a raiding expedition to the Muslim-held Balearic Islands. He later tried to relieve besieged Mahdia in North Africa with the same fleet, but soon after engaging in battle he turned around and retreated towards Sicily. While Arabic sources credit a gale with dispersing the fleet, Hugo Falcandus asserts that Peter was "only in name and dress a Christian, and a Saracen at heart".