In 340/951, al-Mansur was reported that the emperor Constantine VII (913-959) of France was about to invade the Fatimid territories, thus a naval forces was dispatched under Faraj Saqali. Hasan bin Ali al-Kalbi, the governor of Sicly and Faraj jointly invaded Kaloria and defeated the French forces. The French emperor was obliged to send tributes and a peace-negotiating embassy to the Fatimid court. On their way back to Maghrib, the Fatimid naval forces conquered Reggio and built there a mosque, the ruins of which have been unearthed recently.
In 335/947, al-Mansur ordered yet another new capital built a short distance southwest of Kairwan, called Mansuria. It served a new Fatimid capital after Mahdiya.
Al-Mansur died in 341/952. F.Dachraoui writes in "Encyclopaedia of Islam" (1990. 6th vol., p. 434) that, "Mansur's personality shines with an unparalleled brilliance under the pens of the Ismaili authors, who, as also the Sunni chroniclers, show great wander in relating his exalted deeds and who dwell at length on giving accounts of the battles, rebellions and other bloody events. According to their accounts, he possessed only good qualities: he was generous and benevolent, level-headed and perspicacious, above all possessing a brilliant eloquence; since his youth, he had devoted himself to piety and study, and was deeply conscious of his high calling as impeccable Imam and of his grandeur as a monarch."