sentences:  Maó-Mahón was captured in 1287 from the Moors by Alfonso III of Aragon and incorporated into the Kingdom of Majorca, a vassal kingdom of the Crown of Aragon.Its harbour, one of the most strategically important in the western Mediterranean, was re-fortified.In 1535, the Ottomans under Hayreddin Barbarossa attacked Maó-Mahón and took 6,000 captives as slaves back to Algiers, in the Sack of Mahon.