So an Ottoman Sultan who conquered Constantinople would naturally be inclined to anoint himself the new Roman Emperor. Mehmed seems to have taken his new title seriously enough that he had designs not just on ruling the Roman Empire as it was in 1453 (which, frankly, wasn’t all that impressive anymore), but on putting the entire OG empire back together. And if you’re putting the Roman Empire back together, what better place to start than the city of Rome itself? It didn’t hurt that there were apocalyptic Islamic prophecies floating around about the conquest of “Rome” bringing about the End Times. When conquering the “New Rome” (Constantinople) didn’t do the trick, attention shifted to the “Old Rome” (also the actual, you know, Rome). Hence in 1480 the Ottomans invaded southern Italy with a plan to march north and seize the birthplace of the Roman Republic–and, by the way, still the spiritual center of Latin Christendom.