The Osterio Magno is a historic fortified palace of Cefalu.
Handed down for many centuries as the "Domus Regia" of Roger II, the Osterio Magno and facing Osterio Small, non-existent, were built in the thirteenth century, setting them on pre-existing ruggeriane, the powerful family of Ventimiglia of Maro, accounts and subsequently Marquis of Geraci and principles of Castelbuono.
The oldest document in which reference is made all'Osterio Magno is the will, dated January 8, 1387, with which the Count of Geraci, Francesco II Ventimiglia (+1387), establishing its direct heir to his son Henry III Ventimiglia (+1398) .
The palace remained in the hands of Ventimiglia until 1602, when Giovanni III Ventimiglia (1559 - June 12, 1619): Chairman of the Kingdom of Sicily in the years 1595 to 1598 and from 1606 to 1608, he sold it to Simon de Flore. Dead Simone de Flore 3 October 1603, the heirs sold it to the Dominican friars who later, concedendolo in perpetual lease to various people, I divided it into homes, shops, warehouses and even in prison.