 When Muhammad I al-Mustansir, the Hafsid Emir of Tunisia who had put himself under James I of Aragon, died in 1277, Tunisia threw off the yoke of Aragonese suzerainty.Peter first sent an expedition to Tunis in 1280 under Conrad de Llansa designed to re-establish his suzerainty.In 1281, he himself prepared to lead a fleet of 140 ships with men to invade Tunisia on behalf of the governor of Constantine.