It is said that Supino was created by refugees who fled the destruction of Ecetra, the mythical city of Volsci. In Roman times the city was lower down, where today are the ruins of a villa and spas of the second century AD.
During the Middle Ages, following the Barbarian invasions, the inhabitants found refuge in the hills in fortified places under the protection of the abbeys. The first news of Supino is found in the Fossanova Abbey chronicles. Its name comes from the Latin ‘Supinus’ (Locus), and means ‘(place) located on the hillside’.
In 1125 the castle of Supino underwent a long siege, lasting two years, by the troops of Pope Onorio II and passed under the control of the family of the Counts of Ceccano. In 1303, the noble, Rinaldo of Supino took part, with William of Nogaret and Sciarra Colonna, in the famous incident of the slap of Anagni. After several families had control, from the late fourteenth century Supino passed to the Colonna, apart from a short period with the papal state.