Sir Henry Clinton was born in England on April 16, 1730, the son of George Clinton (1686-1761) and Anne Carle (1696-1761). His father served 35 years in the Royal Navy and as governor of Newfoundland (1733-41) and New York (1743-1753), and was the uncle of Henry Fiennes Clinton, 2nd duke of Newcastle. Clinton's mother was the daughter of Major-General Peter Carle. George and Anne Clinton had two additional children: Mary (1727-1813) and Lucy (1729-1750).
Henry Clinton's first military experience came in 1745, when he became a lieutenant of fusiliers in an independent company of infantry. He obtained a commission as a captain the following spring and was involved in the occupation of the French fortress of Louisbourg on Cape Breton during King George's War. By the autumn of 1748, Clinton had risen to the rank of captain lieutenant, and in the summer of 1749 he was promoted to captain and granted leave to go to France.
During this period, the Duke of Newcastle secured Clinton a commission in the Coldstream Guards, where Clinton served from 1751 to 1758. After his time in the unit, he joined the 1st Foot Guards from 1758 to 1762, where he was promoted lieutenant-colonel. During the Seven Years' War, Clinton served with his regiment in Germany, where he was aide-de-camp to Prince Charles of Brunswick. Promoted to colonel, he was wounded in late August 1762 in the Battle of Friedberg, and returned to England where he continued his military career, becoming colonel of the 12th Regiment of Foot in 1766. In 1772, he entered Parliament on behalf of his cousin, the 2nd Duke of Newcastle; in the same year, Clinton was promoted to major general, and in February 1775 he accepted an appointment as third in command of British forces in North America under Thomas Gage and William Howe.
Arriving in Boston on May 25, 1775, Clinton immediately became involved in planning and executing British military strategy. Though successful in persuading a council of war to fortify Dorchester Heights, his recommended action against Nook's Hill was never carried out, and his relationships with Gage and Howe became increasingly strained. Clinton found himself unable to dissuade Gage from launching the attack on Charlestown Neck in the Battle of Bunker Hill that contributed to high British casualties. On September 26, following a lack of success against the rebels, Gage was ordered to transfer his command to Howe, and Clinton became second in command.
After being appointed to lead a detachment of Howe's forces in North Carolina, Clinton sailed from Boston in January 1776. In June of that year, Clinton led a joint force of Howe's detachment and forces newly arrived from England in an assault against Sullivan's Island, which commanded the entrance to Charleston, South Carolina. The attack failed, in part because of a miscalculation of water depth, and Clinton returned north, arriving in Sandy Hook with Charles Cornwallis and a contingent of 45 ships and 3,000 troops. Clinton was present at the Battle of Long Island on August 27, but was unable to convince Howe to accept his plans to destroy Washington's army. He was, however, able to capture Rhode Island on December 8, where he set up winter quarters.
After being granted leave, Clinton arrived in England on February 28, 1777, where he was invested with the Order of the Bath in April and briefed on the British government's plans for the prosecution of the war. Upon his return to New York in July, he learned of the campaign planned by Howe and Burgoyne in his absence, in which Howe would move against Philadelphia and New York while Burgoyne simultaneously invaded from Canada. Clinton failed to convince Howe that the government expected him instead to cooperate with a British force moving south from Canada in a campaign along the Hudson River, and was left to hold New York City while Howe proceeded to Pennsylvania. In early October, Clinton embarked with three thousand troops, intent on going up the Hudson to meet Burgoyne's forces, and on October 5 he was able to capture the Highland forts. A displeased Howe stripped Clinton of his troops, which, combined with Burgoyne's defeat at Saratoga, prompted Clinton to request to resign. Howe could not, however, grant Clinton's resignation as he had already submitted his own and needed to keep Clinton as his presumptive successor. On February 4, 1778, George Germain accepted Howe's resignation and informed Clinton of his promotion to commander-in-chief of the British forces in North America.
After France announced its treaty with the United States on March 13, 1778, Clinton was ordered to send five thousand troops to capture the French colony of St. Lucia and three thousand more to reinforce the Floridas and Britain's position in Nova Scotia and Newfoundland. He evacuated Philadelphia in June and subsequently marched to New Jersey, where, on June 28, he engaged Continental troops at the Battle of Monmouth, the only battle that he commanded during the war. After an inconclusive result, Clinton and his army were ferried to New York to which, after a brief stint in Rhode Island, Clinton returned in September. In November, he sent seven thousand men south in a successful attempt to assist loyalists in the restoration of royal government in Georgia. Despite the promise of success, Clinton remained in New York through the spring and summer of 1779, capturing Stony Point and Verplanck's Point in May, but primarily awaiting reinforcements before embarking on any large military action. When these reinforcements did arrive in late August, Clinton prepared to meet the incoming French forces by withdrawing his forces from the Points and, on October 7, evacuating Rhode Island.
On December 26, 1779, Clinton embarked with Mariot Arbuthnot for South Carolina in an attempt to capture Charleston. The British Army landed near Charleston on February 14, 1780, and besieged the city in an attempt to capture both the city and the large American army quartered there. After Charleston's surrender on May 12, Clinton established the British hold on the South by building armed camps in the South Carolina interior and raising local Loyalist units. Before leaving, Clinton appointed Lord Cornwallis to take command of the British forces in the southern provinces, which numbered approximately 6,500 troops. Clinton returned to New York on June 18, but gradually saw his movements restricted by the arrival of French troops at Rhode Island. Consequently, he moved his army southward, inadvertently focusing the war on Virginia.
Meanwhile, Cornwallis attempted to invade North Carolina, necessitating the transfer of significant reinforcements from Clinton's army. After defeating Horatio Gates at the Battle of Camden, Cornwallis was able to take his remaining force to Virginia, leaving the interior of South Carolina exposed and greatly angering Clinton, who still did not intend to concentrate the war effort on the southern colonies. With the knowledge that the approaching French fleet would make British forces in the Chesapeake vulnerable, Clinton nonetheless allowed Cornwallis to establish a base at Yorktown, where Cornwallis was eventually forced to surrender on October 19, 1781. On that same day, Clinton and Admiral Thomas Graves embarked from Sandy Hook with the intention of engaging the French fleet and relieving Cornwallis position, but the defeat at Yorktown irrevocably handed victory to the Americans.
Clinton's active military career was effectively ended after the defeat at Yorktown, and on April 27, 1782, he received Lord Germain's dispatch accepting his resignation; a day later he was notified that Sir Guy Carleton was appointed his successor. Clinton returned to England in June 1782, where he found his reputation severely undermined by his failure in America and where he subsequently undertook various efforts to defend his actions in the war. His efforts to rehabilitate his reputation included writing pamphlets against Cornwallis and a long unpublished manuscript apologia. Despite his unpopularity, Clinton secured a seat in Parliament from 1790-1794, representing Launceston, Cornwall. On December 23, 1795, after receiving the governorship of Gibraltar, but before he could embark, Clinton died at Portland Place, his home in London.
On February 12, 1767, Clinton married Harriot Carter (ca. 1746-1772), with whom he had at least four children: Augusta (1768-1852), William Henry (1769-1846), Henry (1771-1829), and Harriot (1772-1812). Before their marriage, they may have had an additional child, Frederick, who died in 1774. Clinton also had a daughter, Sophia, with a German woman named Elizabeth Preussen, and several children with his longtime mistress, Mary Baddeley.