The building dates to the 12th Century; commissioned by Charles II of Anjou, it was completed by Robert of Anjou in 1313. The interior has 3 aisles made up of 110 granite columns. The ceiling is domed, with frescoes by Giovanni Lanfranco and Il Domenichino, and the transept has an altarpiece with the renowned painting of the Assumption, by Il Perugino. In the cathedral the skull and blood of the saint is kept and twice a year is said to miraculously liquefy.
