Gilbert, Sir Humphrey (1539–1583), an English soldier and explorer. In 1583 he claimed Newfoundland for England. The fishing settlement he seized, at what is now St. John's, was England's first colony in North America. Gilbert, half-brother of Walter Raleigh, attended Eton and Oxford University. After serving as an officer in Ireland, 1566–70, he was knighted by Queen Elizabeth. A pamphlet he wrote in 1576 inspired the search for a Northwest Passage to Asia. Gilbert's first colonizing expedition, 1578–79, failed. In 1583 he again sailed for America with five ships and 260 men, reaching Newfoundland. Gilbert was lost in a shipwreck on the return trip.