Manuel I (1469-1521) was king of Portugal from 1495 to 1521. Known as "the Fortunate," he oversaw the formation of the Portuguese Empire and strengthened the position of the monarchy.

The son of the Duke of Viseu, Manuel was born on May 31, 1469, at Alcochete. He was the cousin and brother-in-law of King John II of Portugal. The heir to the throne, Prince Afonso, was killed in an accident in 1491, and thereafter the royal succession devolved upon Manuel.

Manuel married in turn two daughters of the joint rulers of Castile and Aragon, Ferdinand and Isabella; his third marriage was to their granddaughter Leonor, sister of the emperor Charles V. Manuel's Spanish marriages extracted from him a reluctant promise to Ferdinand and Isabella to expel all Portuguese Jews. Himself unmoved by anti-Semitic passions, he accepted the "technical conversion" of the Jews, granting them a 20-year period of grace before allowing inquiries to...