The city has Roman origins, but it retains traces of its past only from the medieval era, of which we can admire the splendid Romanesque buildings, the church, the cathedral and the bell tower. The residential part has developed over the centuries, mostly during the Renaissance. The early medieval origin fortress overlooking the village has been expanded between the thirteenth and fourteenth centuries, when the Malatesta conquered San Leo subtracting it to the Montefeltro.
From 1791 until his death on August 26, 1795, Giuseppe Balsamo, known as Count Alessandro di Cagliostro, was imprisoned.