WARREN, Sir Peter, British naval officer, born in Ireland before 1703 ; died there, 29 July, 1752. He entered the navy in 1727, and had attained the rank of commodore in 1745, when he was appointed to command an armament that was intended for an attack on Louisburg. He joined the fleet of transports with the land forces under Sir William Pepperrell from Boston, in Casco bay, on 25 April, with four ships, carrying 180 guns. On 30 April the combined forces appeared before Louisburg, and on 1 May the siege was begun. (See PEPPER-BELL, WlLLIAM.) On 18 May, Captain Edward Tyng, in the "Massachusetts " frigate, captured a French man-of-war of 64 guns, with more than 500 men and a large quantity of stores for the garrison, and this success greatly raised the spirits of the besiegers. Warren's fleet was re-enforced by the arrival of three large ships from England and three from Newfoundland, and, serious breaches been made in the walls, it was determined to order a general assault; but the French commander, seeing that further resistance would be useless, surrendered the fortress on 16 June. By the capitulation, 650 veteran troops, more than 1,300 militia, and other persons--in all about 4,000--agreed not to bear arms against Great Britain during the war. Seventy-six cannon and mortars, and a great quantity of military stores, were also taken. The French loss in killed was 300; the English was 130, but the latter suffered heavily from disease. Pepperrell was made a baronet for his share in the victory, and Warren was promoted to rear-admiral, 8 August, 1745. He aided in defeating a French squadron off Cape Finisterre in 1747, capturing the greater part of it, and in the same year was elected to parliament for Westminster. Sir Peter married Susan, eldest daughter of Stephen De Lancey, of New York, and was the owner of a valuable estate in the Mohawk valley, which he placed in charge of his nephew, William, afterward Sir William Johnson.