Claiborne was born probably in Crayford Parish, in Kent, England, where he was baptized on August 10, 1600. He was the son of Sara Smyth James Cleyborne and her second husband, Thomas Cleyborne, a merchant and former mayor of King’s Lynn in the county of Norfolk; Sir Roger James, a shareholder in the, may have been his elder half brother. Contemporaries wrote Claiborne’s surname with a variety of phonetic variants, and during his first decades in Virginia he sometimes spelled his name Claybourne, but in later years he signed as Claiborne. He entered Pembroke College, University of Cambridge, on May 31, 1617. Four years later, perhaps on his half brother’s recommendation, the Virginia Company appointed Claiborne surveyor of the colony at a salary of £30 per annum and also offered him an assistant, 200 acres of land, and a convenient house, presumably in .
Claiborne traveled to Virginia in the retinue of Governor Sir Francis Wyatt and arrived in October 1621. His first task was to survey the New Town section of Jamestown, but he was soon involved in Virginia’s politics and was one of the company’s officers who in 1622, following the deadly, requested that the king take over management of the colony. By the spring of 1623 Claiborne was a member of the governor’s Council, in which office confirmed him in August 1624 when appointing Wyatt the first royal governor of Virginia. Surveying allowed Claiborne to accumulate a considerable amount of land, including property in Elizabeth City County. After 1640 he lived at Romancoke, near the confluence of the Mattaponi and Pamunkey rivers, in the part of York County that in 1654 became New Kent County and in 1701 King William County. In the mid-1630s he married Elizabeth Boteler, or Butler. They had four sons and two daughters.
Late in the 1620s Claiborne explored trading opportunities in the upper part of the Chesapeake Bay and for much of the 1630s operated a lucrative trading post on Kent Island, which put him in conflict with successive Lords Baltimore, who maintained that the island was within the charter boundaries of Maryland. Eventually expelled from the island and losing perhaps as much as £10,000, Claiborne harbored a long and intense animosity toward Maryland and the Calvert family. Beginning with tobacco and fur, Claiborne built a profitable and influential commercial network that connected the Chesapeake Bay with London. His closest Virginia associates included Samuel Mathews (d. 1657), another merchant, land magnate, and member of the governor’s Council, and his initial London associates were William Cloberry and Maurice Thompson, two of the most successful merchants in that city. In 1638 Claiborne received a grant of an island off the coast of Honduras and may have intended to set up a trading post there.
Claiborne made several voyages across the Atlantic to advance his commercial interests and protect his political connections. Growing wealth and influence made him a leader of Virginia’s emerging political elite. In 1626 Claiborne became secretary of the colony, an office that ranked second only to the governor in political weight. He and Mathews led a dominant faction of Council members whose quest for land and influence produced clashes with Governor Sir John Harvey. In May 1635, while Claiborne was at Kent Island, the faction evicted Harvey from office. Claiborne initially emerged from that feud a much stronger politician, and when Sir Francis Wyatt returned to Virginia as governor in November 1639, he handled Claiborne gingerly.
Claiborne yielded the secretary’s lucrative office to his rival, who in 1634 arrived with a royal appointment, and when Harvey returned to Virginia for a second term as governor in 1637 Claiborne lost his seat on the Council. In 1640 he scored a victory over Kemp by obtaining royal permission to found a signet office for the purpose of validating public records, providing the Council consented, which it did. The new office reduced Kemp’s influence and income because the great seal of Virginia and its attendant fees were transferred from him to Claiborne. Not long thereafter Wyatt relinquished the office of governor to Sir William Berkeley. Claiborne acted as an intermediary, and in 1642 the new governor reappointed Claiborne to the Council and named him treasurer of the colony.
The two dominant figures in Virginia, Claiborne and Berkeley contested for leadership of the planter elite. They differed over trade policy, with Claiborne opposing Dutch traders whose presence in Virginia threatened his own connections with London. They disagreed over how to prosecute the Anglo-Powhatan War of 1644–1646, during which Claiborne commanded some of the Virginia militia and made an attempt to recover Kent Island. They also took different positions on the issues that led to the English Civil Wars. Claiborne readily accommodated himself to the Puritans and was one of the commissioners Parliament appointed to bring Virginia and Maryland under its dominion. In that capacity he helped negotiate the terms by which Berkeley surrendered Virginia to Parliament in March 1652. Claiborne and his fellow commissioner, who succeeded Berkeley as governor of Virginia, appointed a new Council in Maryland, action that precipitated two years of intermittent warfare between competing factions in that colony.
In the spring of 1652 theelected Claiborne senior member of the Council and secretary of the colony. He and Berkeley remained on civil terms, despite their differences, and Claiborne eased Berkeley’s return to the governorship in March 1660. Berkeley retained him in office for a few months, but Claiborne was too deeply implicated in the parliamentary cause to continue as a Council member and secretary after Charles II returned to England as king. Claiborne retired from public life in March 1661 and lived quietly and in relative obscurity at Romancoke. Berkeley threw a few crumbs in his direction by appointing two of his sons to the county court, and one of Claiborne’s sons sat in the House of Burgesses. Claiborne remained loyal to the governor during Bacon’s Rebellion in 1676, suffered significant property losses in the process, and may have sat on some of the courts-martial that sentenced several rebels to death, although it is possible that Claiborne’s namesake son took on that responsibility. On March 13, 1677, Claiborne petitioned the Crown to recoup financial losses he had incurred when he was expelled from Kent Island forty years earlier. The following July 16 a Colonel Claiborne, who may have been the father, the son, or an unrelated person, boarded the royal naval ship Bristol to collect eight barrels of shot for use by the county militia.
The date and place of Claiborne’s death are not known, nor is the place of his burial. He died on an unrecorded date before August 25, 1679, when his son Thomas Claiborne was identified in a York County record as executor of the estate of “Coll William Clayborne Decd.”