From 1504 to 1506, following his attempted escape from the Castel Sant'Angelo, the Castillo de la Mota acted as a prison for Cesare Borgia. Cesare's location was kept a closely guarded secret between Pope Julius II and King Ferdinand II of Aragon; not even the Mentor of the Italian Assassins – Ezio Auditore – was allowed to know of Cesare's whereabouts.