Admiral, a naval officer of the highest rank. The title was introduced by the Genoese and other Italians into Europe, and was probably derived from the Arabic word amir, which was also used in reference to shipping by the Greeks of the lower empire. The office of admiral was not created for the navy of the United States until during the second year of the civil war. Previously the grade of captain was the highest in the service, although the title of commodore had been accorded to commanders of squadrons and naval stations, and they had assumed the commodore's distinguishing broad pennant. By act of congress, Jan. 16, 1857, captains in command of squadrons were denominated flag officers, and by subsequent and progressive departmental orders and regulations they substituted for the broad pennant a square blue flag worn at the mizzen; next the same at the fore for those over 20 years commissioned as captain, and the senior captain's was carried at the main; finally they came to arrogate all of the functions of admirals. Congress established the grade of rear admiral July 16, 1862, and commissioned therein on account of eminent individual services David G. Farragut and three other captains from the active list, and Charles Stewart and ten other distinguished veterans from the retired list.

The grade of vice admiral was constituted by act of Dec. 21, 1864, and Farragut promoted thereto as a reward for Mobile; and as a further token of gratitude and honor the grade of admiral was created for him July 25, 1866. The rank of admiral is relatively equivalent to that of general in the army, vice admiral to lieutenant general, and rear admiral to major general. The pay per annum of admiral is $13,000; the sea pay of vice admiral $9,000, and of rear admiral $6,000. There have been bestowed 2 commissions of admiral, 3 of vice admiral, and 55 of rear admiral; and there are now in the service 1 admiral, 1 vice admiral, and 38 rear admirals; of the latter, 12 are on the active and 26 on the retired list. - In Great Britain there were until 1864 three classes of admirals, red, white, and blue. The distinction of flags was then abolished, and only the white flag retained in the royal navy. The management and superintendence of the navy of England was formerly vested in a lord high admiral. James II. when duke of York held this office, and when king, on account of his predilection for the naval service, kept it in his own hands. Prince George of Denmark, husband of Queen Anne, was also lord high admiral.

The last incumbent of the office was the duke of Clarence, afterward William IV., who held it from May, 1827, till September, 1828, since which time the office has been put in commission, the duties being performed by the lords of the admiralty, who are six in number, the first lord having a seat in the cabinet. His pay is £4,-500 per annum. - The highest officer in the Russian navy bears the title of general admiral.