Of Roman origin, Known from 1014 as Castiglione aretino
untill, in 1384, when Florence took over the Aretin Republic,
it became "Fiorentino".
Its medioeval girdle of walls, dominated by Cassero fortress, remais intact.
The historic center consists entirely of dignified maisons, both sacred and secular, amaong which the most notable are the Gotic church of  S. Francesco, the Collegiate church and the
Gesù church, all of them rich in art works of high value. In the 16th-century Palazzo Comunale there is a rich library
with paintings, tablets and priceless goldwork of the 12th to
15th centuries.A short distance beyond the walls is the church of Consolation
(Renaissance) of octagonal plan.