Stephen Kemble was born in 1740 in New Brunswick, N.J., the fourth son and fifth child of Peter Kemble and his first wife, Gertrude Bayard. The Kemble family were related to several of the most influential and politically powerful New York families of the colonial period, including the van Cortlandts, Bayards, and Stuyvesants. Like many of their station, the Kemble family remained staunchly loyal to the British cause throughout the Revolution.
After attending school at the College in Philadelphia, Stephen Kemble accepted an ensign's commission in the 44th Regiment of Foot at the age of 17. Under Lord Howe, he participated on the campaign that resulted in the repulse of Fort Ticonderoga, and on 24 January 1765, he was transferred to the captaincy of the First Battalion of the 60th (Royal American) Regiment. His rise through the ranks of the British army was no doubt facilitated by his close personal relationship with Thomas Gage, the commander-in-chief of British forces in North America, who had married Kemble's sister, Margaret in 1758.
In 1772, Kemble's friendship with his brother-in-law paid dividends as he was selected to replace an ailing Richard Maitland as Deputy-Adjutant-General of the Forces in North America, a position that placed him at Gage's side and that carried with it a rank of "Major in the Army." Kemble traveled to England in the next year, a trip during which he stopped at the house of Jeffrey Amherst and 'kissed hands' with George III, but on his return, found himself in an unenviable position surrounded by the highly volatile populace of Boston. Kemble's journals reveal him to have been unwaveringly devoted to the British cause and suggest the depth of his personal loyalty to Gage, and he acquitted himself well throughout the crisis.
The first of several changes in fortune for Kemble took place, however, when William Howe replaced Gage as commander-in-chief in October, 1775. In anticipation of the arrival of German auxiliaries, Howe felt it necessary to appoint an officer of higher rank to serve as Deputy-Adjutant, and chose Francis Rawdon-Hastings (later the 2d Earl of Moira). Thus, in 1776, Kemble found himself demoted to second in charge of an office that he had previously commanded, but because of good personal relations with both Rawdon and Howe, he chose to remain in his position.
Upon Rawdon's resignation in October, 1779, Kemble expected that he would be promoted to replace the man for whom he had worked so diligently, and whose position he had, in fact, once held. Unfortunately, Henry Clinton, the commander-in-chief, held a particular, personal disregard for Kemble, and proceeded to appoint another candidate, the junior officer John André. Kemble was incensed at this replacement, which formed an ironic counterpoint to his previous replacement by the senior officer Rawdon, and after some negotiations with Clinton, Kemble resigned to resume his commission as Lieutenant Colonel of the First Battalion of the 60th Regiment.
Kemble and regiment sailed to Montego Bay, Jamaica, arriving in January 1780, where he found that Governor John Dalling had, with approval of Lord North, organized a joint military and naval operation for the reduction of the Mosquito Shore, with the goal of taking control of the St. John River, Lake Nicaragua, St. John's Castle (situated on the river on the approach to Lake Nicaragua), and several Spanish settlements around the lake and on the Pacific Shore, thus severing communications between the northern and southern Spanish American colonies.
Kemble immediately offered his services to Governor Dalling for the expedition, but Dalling initially refused on the grounds that military command had already been promised Capt. John Polson (also of the 60th Regiment) and naval command to the 22 year old Horatio Nelson. The expedition embarked on 4 March 1780, heading first for Cape Gracias a Dios to pick up some Mosquito Indians who were alleged to be disaffected with the Spaniards and to rendezvous with a small flotilla raised by English settlers along the Black River (now in Honduras). When Polson and Nelson found that the English had not arrived as expected, and that the Indians had been 'tampered with' by Spanish agents, they proceeded southward, arriving at St. John's Harbour (now in Nicaragua), on the 24th. There, meeting no opposition from the Spanish, they sailed up the St. John's River toward Lake Nicaragua, and surrounded the Spanish garrison at St. John's Castle (64 miles up river from the harbor, 32 miles from the Lake) on the 13th of April.
Meanwhile, Dalling ordered Kemble to join the expedition on the 2d of April 1780, and he gathered 250 regular army reinforcements plus 270 men from a new corps (referred to as the Jamaica Legion or Jamaica Volunteers) and arrived at St. John's Harbour to assume command on the 24th. Kemble was promoted to the rank of Brigadier-General for the duration of the expedition.
The force at St. John's Castle, under the direction of Nelson, Polson, and chief engineer Edward Marcus Despard, worked through stifling heat and strenuous conditions to bring artillery and heavy ordnance up for support. Without any dramatic assault, they forced the Spaniards to capitulate on the 29th of April after the defenders depleted their supply of drinking water. The success of this mission was greeted with euphoria in Jamaica; Dalling proclaimed that "the door to the South Seas is burst open," apparently believing Indian rumors that through the lake lay a secure shipping passage to the Pacific.
Almost immediately, however, major problems arose. The diversion to Cape Gracias a Dios and the slow passage up the St. John's River had caused the timetable to span over three months, rather than the planned four weeks, and this delay promised to extend the mission into the rainy season when health concerns became preeminent and travel was difficult at best. Nelson was taken with dysentery and fever in late April and was sent away in such a weakened condition that he had to be carried onto the transport to Jamaica.
Sickness began to decimate the troops, and by mid-May, there were not even enough able bodied men to perform the duties of the camp. By June, only 10 of 250 men were fit for duty. The Indians whom the British had hired for the expedition began to desert in great numbers, taking with them the pitpans (boats) used to transport supplies, the sick and wounded. Realizing that advance toward the lake was impossible at this point, Kemble ordered a dispatch of troops to hold St. John's Castle and another small outpost, called Cooke's Post, further upstream, and he removed the remainder of his troops to St. John's Harbour.
Throughout the summer, attempts were made to reinforce the expeditionary force with English settlers from Rattan (an island off the coast of Honduras) and the Black River area, and the army contracted for the slaves of local planters to work as camp laborers. Concurrently, in the late summer, Edward Gleadowe, Colvill Cairns and James Thomson were sent on an expedition to 'reconcile' the Mosquito Indians: by negotiation and the exchange of gifts, the British hoped to sway the Indians to their side and perhaps to convince them to participate in a planned attack on Spanish settlements late in the year. Although Cairns and Thomson were successful in bringing about a treaty between the Mosquitos and British, serious logistical problems in transporting supplies to the garrisons, sickness, and desertion continued to plague the expedition. By the end of September, only 320 of the 1400 or more sent on the expedition were left alive, and perhaps only half of these were fit for duty. Recognizing that maintaining the garrisons at both ends of the St. John's River was not possible, Dalling ordered that St. John's Castle be destroyed and Nicaragua evacuated.
Following the unmitigated disaster in Nicaragua, Kemble returned to England. He was promoted to full Colonel in the Army (20 November 1782), and returned to duty with his regiment on Grenada, where he remained in charge of the garrison at Fort George. In 1786, after another very brief visit to England, Kemble was ordered to Quebec, where he once again found himself placed under the command of an officer who was technically of an inferior grade. After his complaints to the War Department were ignored, Kemble retired from military service.
Kemble spent part of 1788 in New Brunswick, where he and a brother had some property interests, but returned to London at the beginning of 1789. He was appointed Deputy Judge Advocate in America in 1793, and in 1797, Deputy Judge Advocate for an expedition intended for Europe. In 1805, Kemble sold his English property and returned to live in the house in which he had been born, and which he still owned, in New Brunswick, N.J. He died in 1822, and is buried in Christ Church, New Brunswick.