| Sebastian | |
|---|---|
.jpg) Portrait by Cristóvão de Morais, c. 1571–74 | |
| King of Portugal | |
| Reign | 11 June 1557 – 4 August 1578 |
| Coronation | 16 June 1557, Lisbon |
| Predecessor | John III |
| Successor | Henry |
| Regents | Catherine of Austria (1557–1562) Henry of Portugal (1562–1568) |
| Born | 20 January 1554 Ribeira Palace, Lisbon, Kingdom of Portugal |
| Disappeared | 4 August 1578 (aged 24) Ksar el-Kebir, Saadi Sultanate |
| House | Aviz |
| Father | João Manuel, Hereditary Prince of Portugal |
| Mother | Joanna of Austria |
| Religion | Roman Catholicism |
| Signature |  |
Sebastian (Portuguese: Sebastião I[1] [sɨβɐʃˈti.ɐ̃w]; 20 January 1554 – 4 August 1578) was King of Portugal from 11 June 1557 to 4 August 1578 and the penultimate Portuguese monarch of the House of Aviz.
He was the son of João Manuel, Prince of Portugal, and his wife, Joanna of Austria. He was the grandson of King John III of Portugal and Catherine of Austria, Queen of Portugal. He disappeared (presumably killed in action) in the battle of Alcácer Quibir, against the Saadi Sultanate of Morocco. Sebastian I is often referred to as the Desired (Portuguese: o Desejado) or the Hidden (o Encoberto), as the Portuguese people longed for his return to end the decline of Portugal that began after his death. He is considered to be the Portuguese example of the King asleep in mountain legend as Portuguese tradition states his return, in a foggy dawn, in Portugal's greatest hour of need.
- ^ Rendered as Sebastiam in Archaic Portuguese