king of Portugal and Roman Catholic ecclesiastic whose brief reign (1578–80) was dominated by the problem of succession. His failure to decisively designate a successor left the Portuguese throne at his death prey to its Spanish claimant, King Philip II.

Henry, son of Manuel I, chose a career in the church and became, successively, archbishop of Braga (1534), Évora (1540), and Lisbon (1544), attaining the rank of cardinal in 1545. For a time he headed the Portuguese Inquisition. He also became a staunch supporter of the Society of Jesus and founded the Jesuit university in Évora (1558).

Henry served as regent until 1568 in the latter part of the minority of his grandnephew Sebastian (reigned 1557–78). After Sebastian's death in a disastrous defeat by the Moors at Alcazarquivir (Battle of the Three Kings), the aged, celibate Henry was named king. Unable to resolve the succession question, he named five governors to act as regents on his death. Spanish occupation eight months later put Philip on the throne.