Riano is located between Via Flaminia and Via Tiberina, along the Tiber river valley.
Riano belonged to the Etruscans and then the Romans when it was conquered. A colony of Legionaries from the Illyrian or Dalmatian regions settled there. From this comes perhaps the ancient name of Rascianum, Ruscia was the ancient name of Serbia. In order to stabilize their victories, the Romans, in fact, gave the conquered lands to the colonies of legionnaires as a prize.
Since the fall of the Roman Empire several Barbarians, Goths and Lombards came until 774, and the only defenders of Rome in this long period were Popes such as Gregory the Great and Leo III crowned emperor Charlemagne in 800. After Charlemagne the riots began again and the Saracens arrived.
Out of these disorders feudalism was born. Around a thousand people sought refuge in the hills within fortresses called ‘Castrum’. The first document of the Riano Castrum is from 1151 when the castle was given to Pope Adrian IV, who then transferred it to the Benedictine monks of St. Paul Outside the Walls.
Destroyed after a long siege by Stefano Colonna in 1321, it was rebuilt by the monks of St. Paul, to which it belonged until the sixteenth century. It was later owned by the Caddi, of Cesi and, in the eighteenth century, the Ruspoli.