In Roman times, it was known as Pedum.[3] A castle is mentioned here in 984 AD, called Castrum Gallicani. Here a Benedictine monastery grew in the following year, later owned by the abbey of San Paolo fuori le Mura. Gallicano from the 13th century it was a possession of the Colonna family, and pope Martin V (a Colonna) sojourned here in 1424.