Portuguese navigator; served his country first in the East Indies and Morocco, but dissatisfied with King Manuel's treatment of him, offered himself to Spain; under Charles V.'s patronage he and Ruy Falero set out to reach the Moluccas by the west in 1519; he reached the Philippines, and died in battle in Matan; on this voyage he discovered the Magellan Strait, 375 m. long and 15 m. wide, between the South American mainland and Tierra del Fuego; he gave name to the Pacific from the calm he exceptionally, it appears, experienced on entering it (1470-1521).