Claiborne, William (klāˈbərn) [key], c.1587–c.1677, Virginia colonist, b. Westmorland co., England. He emigrated to Virginia in 1621 as official surveyor and then served as secretary of state (1626–37, 1652–60) of that colony. He traded with the Native Americans, explored near the head of Chesapeake Bay, and established a fort and settlement on Kent Island in the Chesapeake. He opposed the grant of Maryland to Lord Baltimore, and after Baltimore's order (1634) for his arrest, Claiborne undertook armed resistance from his stronghold. Claiborne went (1637) to England to justify his conduct, but the issue was decided in favor of Lord Baltimore. In 1642, Claiborne was made treasurer of Virginia, and several years later, claiming the authority of Parliament, he invaded Maryland and drove out the governor, Leonard Calvert. He controlled Maryland for several years and was a member (1652–57) of its governing commission.