ALFONSO VI, king of PORTUGAL. - Born in 1643, he succeeded his father John IV, king of Braganza, who in 1640 had detached the kingdom from Spain. He therefore had to continue the war with Philip IV; but with the victory at Almeixal (1663) and at Villaviciosa (1665) he secured Portugal’s independence forever. His marriage to Maria Francesca Isabella of Savoy (1666) was unhappy, for when the queen saw herself abandoned by her husband she allied herself with her brother-in-law Don Peter, and together they managed to have A. deposed by the *cortes* and exiled on the pretext of mental alienation. Later transferred to Cintra, he died there in 1683.
Bibl.: P. Viegaz, Principios del reino de Portugal, Lisboa 1671; F. de Almeida, Historia da Igreja em Portugal, s. v., cols. 1922-26. Giuseppe M. Pou y Marti