SEBASTIANO, king of PORTOGALLO. - B. in Lisbon on 20 Jan. 1554, d. at Ksar el-Kebir (Morocco) on 4 Aug. 1578.
The penultimate king of the Aviz dynasty, nephew of Carlo V (whose daughter was his mother Giovanna), he was proclaimed king at the age of three upon the death of his uncle Giovanni III; after the two regencies of his grandmother Caterina and his uncle, Cardinal Enrico, he became king in fact in 1568.
Educated by don Aleixo de Meneses and the Jesuit Luis Gonçalves de Camara, who instilled in him that mystical and chivalric character which places him within the great religious and military tradition of the Lusitanian monarchy, S. enacted severe laws against luxury and corruption and carried out an administrative decentralization in the Indies. S. acquired a reputation as a visionary and mystic, yet his government devised various realistic African enterprises: he conquered the Kingdom of Monomotapa in south-eastern Africa, but failed to extend his dominions in northern Africa. In 1571 he accepted Pio V's invitation to form a league against the Turks, without taking part in the battle of Lepanto. Learning of dynastic dissensions in Morocco, he decided upon the African expedition in 1577, with the aid and encouragement of Gregorio XIII and against the advice of Filippo II. He departed on 2 June 1578 and on the fields of Ksar el-Kebir fought the epic battle in which, defeated, he died a hero. Two years later (1580) Portugal lost its independence through the action of Filippo II of Spain.