In the 13th century the marriage of Manfredi Chiaramonte to Isabella Mosca, united the two Sicilian counties of Modica and Ragusa.
The family's great power in Sicily lasted until 1392 with the execution of Andrea Chiaramonte, 8th Count of Modica, last defender of Palermo for King Frederick IV of Sicily against the illegitimate pretender Martin I of Aragon.
The palazzi subsequently became the residence of Martin I of Aragon and of Blanche de Navarre, then the Spanish viceroys, and then a prison of the Inquisition.
Today, the palace's much copied and distinctive form of Norman Gothic architecture is known, in Sicily, as the Chiaramontan style.
Traditionally, direct male descendants of Manfredi are called Pietro, Ugo or Flavio – Pietro the foundation stone, Ugo the king of Sicily and Flavio because of Sicily's bright yellow sun.