Lord of the Manor of Stapleford. Sir John commanded the Royal Navy during the War of American Independence and the Napoleonic Wars, in which he became a Rear Admiral. Amongst his many honours he was made Knight of the Bath and Knight of the Hanoverian Order Guelph. For several years he was a Member of Parliament for Nottingham.

John Borlase Warren was entered as an able seaman on the books of the Marlborough on 24 April 1771, although he had been admitted to Emmanuel College, Cambridge, in 1769. His college and naval careers were intermingled, and he graduated with a B.A in 1773 and an M.A. in 1776. In 1774 Warren had been elected to parliament for Marlow in Buckinghamshire (he sat for several constituencies between then and 1807), and on 1 June 1775 he assumed the baronetcy that had been extinct since the death of his great-grandfather.

Warren served on the North American station during the American Revolutionary War, mainly aboard frigates and sloops, and was promoted lieutenant in July 1778 and captain in April 1781. In the French revolutionary wars he commanded a frigate squadron which captured most of a similar French force on 23 April 1794, and for this action was made a knight of the Bath. Warren was unleashed on the French coast with another frigate squadron in 1796 and captured 220 sail, including 37 naval vessels. With three sail of the line and five frigates, he caught a French squadron with 5,000 troops off the west coast of Ireland on 10 Oct. 1798, captured four ships, and scattered the rest. He received the thanks of the British and Irish parliaments and a gold medal. Warren served in the Mediterranean in 1801, and in 1802 undertook a special mission to St Petersburg (Leningrad, U.S.S.R.) to congratulate Emperor Alexander I on his accession. Promoted rear-admiral on 14 Feb. 1799, he became vice-admiral on 9 Nov. 1805 and an admiral on 31 July 1810. Between November 1807 and July 1810 he was commander-in-chief of the Halifax station.

HMS Shannon and the USS Chesapeake exchange broadsides during their 15-minute battle on 1 June 1813 in Robin Brook's painting Duel off Cape Anne. The Shannon's lopsided triumph brought to an end a string of U.S. frigate victories in the War of 1812.

Warren’s major North American service came during the War of 1812. As admiral of the blue he was appointed on 3 Aug. 1812 to the Halifax, Leeward Islands, and Jamaica stations, the Admiralty having unified the three commands to allow him to direct the overall naval strategy of the war.

Warren’s initial task upon his arrival at Halifax in September was to negotiate an end to the conflict with the American secretary of state, James Monroe. After this attempt failed, he laid out his strategy of fighting a defensive war off the North American coast to protect trade, while keeping up limited blockades of American waters with forces operating from the two main bases of Halifax and Bermuda. Writing privately in December to Lord Melville, his patron at the Admiralty, Warren argued that a series of raids on the enemy coast, and selective blockades until reinforcements were sent, would keep American military forces tied down and relieve pressure on British North America.

To strengthen inland naval defences, Warren advised the Admiralty to send a force to the Canadian lakes, a recommendation which was followed in March 1813 with the ordering out of seamen under Sir James Lucas Yeo*. Warren also urged Sir George Prevost*, the military commander in North America, to build more ships on the lakes, and dispatched three of his lieutenants, Robert Heriot Barclay*, Daniel Pring*, and Robert Finnis, there.

Unfortunately for Warren, the force at his disposal always lacked ships, seamen, provisions, and stores, even after reinforcements arrived. His incessant requests probably irritated the Admiralty, and he was reprimanded for them by its secretary, John Wilson Croker. Yet Warren’s vessels had to blockade the main American ports from New York City south, watch and restrain scores of privateers, be alert for forays by the American frigates and sloops, guard the convoys from Jamaica to Quebec, protect Halifax and Bermuda, and carry out raids on the coasts of Chesapeake and Delaware bays.

He was relieved in March 1814, when the Admiralty re-established independent stations and appointed Sir Alexander Forrester Inglis Cochrane to the North American one. Warren was embittered enough to protest to Lord Melville and to hold up transfer of the command to Cochrane until 1 April. Apart from the blow to his prestige, Warren was concerned that the loss of command would exclude him from receiving prize money. The station commander was allowed a percentage of the proceeds from the sale of every captured vessel, and Warren kept a secretary just to record captured vessels and his potential earnings.

Writers on the War of 1812 such as William James, Alfred Thayer Mahan, Cecil Scott Forester, and John K. Mahon have considerably undervalued Warren’s achievements. But his earlier career reveals that he was at times a dashing and successful tactician. His conduct of the naval war, while not marked with spectacular successes, nevertheless helped to relieve the pressure on the Canadas and meshed well with Prevost’s land strategy.

The defeat of Napoleon in the spring of 1814 allowed a rapid build up of men and material, and permitted the Admiralty to consider a more aggressive strategy than Warren’s defensive approach with limited resources. By that time, however, Warren had returned to England, and he retired with a gcb in 1815.