Constantino decided that he needed a more defensible location as the Capital of Empire - how did that work out. Just over a century after the Conquest of Spain, the Muslims briefly took Rome, they did it by sailing up the Tiber. They couldn't hold it, the fate of Italy was decided at sea. The Arabs did hold on to Sicily but not the mainland. Eventually Genovese and Napolitan "pirates" sacked Carthage, it was to be the last time. The city was abandoned and a new one built further inland - modern day Tunis.