King Sebastian (1554-1578), reigned between 1557 and 1578
The Royal Palace at the castle was this monarch’s favourite residence.
Shortly after his coronation, extensive rebuilding and restoration works were carried out in the Palace, which had been badly affected by the 1531 earthquake.
Some work was also undertaken at the castle: the Torre do Tombo was enlarged and some documents were archived in palace chambers.
We have a proposal for the transformation of the area by the humanist Francisco de Holanda: The buildings that Lisbon lacks (1571). Dedicated to King Sebastian, it recommends a profound renovation of the city : at the top of the hill, there would be a modernised castle, with a hexagonal layout, equipped with “strong palaces” inside – a fortified palace.
The most complete description of the Royal Palace at the castle dates from the same year, written by João Baptista Venturino, the secretary of Cardinal Alexandrino, legate of Pope Pius V. The report details the exterior and interior of the old palace, including the various chambers and valuable pieces, which evokes an image of a series of interconnected constructions that had been erected over centuries.
With the Philippine dynasty, the prominence of the old citadel was irreparably broken. . It did not lose its military character, but acquired new roles, particular those related to healthcare and prisons.