Construction of the Castle began in 1316, by order of Count Francesco I of Ventimiglia, over the ruins of the ancient Byzantine town of Ypsigro, high on the San Pietro hill.

Numerous drastic alterations were made in the 17th century for reasons of accommodation, when a number of Ventimiglia families moved here from Palermo - the castle never served any really strategic purpose, owing to its geographic position down valley.

The Cappella Palatina ("Palace Chapel") was built in 1683 by the brothers Giuseppe and Giacomo Serpotta, with a great profusion of precious marble, stuccowork, putti, and friezes that commemorate the most resplendent moments in the history of the House of Ventimiglia.

It preserves prized works, most remarkably, above the main altar, a splendid polyptych depicting The Coronation of the Virgin , attributed to Pietro Ruzzolone or possibly Antonello de Saliba.

• Francesco "Frank" Lanza, reputedly the first boss of Sicilian-American Mafia family in San Francisco, U.S.A. • James Lanza, (Born: Mariano Vincenzo Proetto on October 23, 1902, in Castelbuono, to Francesco Proetto and Caterina Albanese – Died: February 14, 2006) was reputedly a Sicilian-American mobster and boss of the San Francisco crime family.