Battle of Alcácer Quibir
The Cardinal Henry, great-uncle of Sebastian I of Portugal, became ruler in the immediate wake of Sebastian's death. Henry had served as regent for Sebastian after 1557, and succeeded him as King after the disastrous Battle of Alcácer Quibir in 1578. Henry renounced his clerical offices and sought to take a bride for the continuation of the Aviz dynasty, but Pope Gregory XIII, affiliated with the Habsburgs, did not release him from his vows. The Cardinal-King died two years later, without having appointed a Council of Regency to choose a successor.