Cavendish, Thomas, 1560–92, English navigator. He commanded a ship in the flotilla under Sir Richard Grenville sent (1585) by Sir Walter Raleigh to establish the first colony in Virginia. In 1586, in command of three vessels, he sailed from England on a voyage round the world (the third to be made), crossing from the coast of W Africa to Patagonia, where he discovered a fine harbor that he named Port Desire. He ravaged Spanish towns and shipping on the west coast of South America and thence continued his journey by way of the Philippines, East Indies, and Cape of Good Hope, returning to England in 1588 after a voyage of more than two years. A second circumnavigation that commenced in 1591 ended disastrously; his fleet of five ships was dispersed, and he died at sea.