Sebastian Cabot (ca. 1482-1557), an Italian-born explorer in the service of England and Spain, made significant discoveries in an age of geographical discovery.

Sebastian Cabot, the son of John and Mattea Cabot, was probably born in Venice, where he is documented as a small child in 1484. He accompanied his parents to Spain and England, but he would have been too young to sail with his father on the Atlantic voyages of 1497 and 1498. Although Sebastian had not yet commanded an expedition of his own by 1505, Henry VII of England awarded him an annual pension of £10, perhaps because of his growing proficiency in cartography and navigation.

Cabot almost certainly made a voyage for England in 1508-1509, in which he sailed far northward and discovered the entrance to Hudson Bay. He considered this to be the water passage leading around North America to the Orient. On his return to England, Henry...