Britain
John "Jacky" Fisher
1841–1920 First Sea Lord, 1904–1910 and 1914–1915
Fisher joined the Royal Navy at 13 and became its most forceful reformer. As First Sea Lord from 1904 he scrapped scores of obsolete ships, concentrated the fleet in home waters, championed submarines, destroyers and oil fuel, and forced through the dreadnought and the battlecruiser. His enthusiasm and fierce temper made him enemies, and he feuded with his rival Lord Charles Beresford. He retired in 1910 but was recalled in October 1914 by Winston Churchill. He resigned in May 1915 over the Dardanelles campaign, which he thought drained resources from the North Sea. His dreadnought gave Britain a new lead and, ironically, gave Germany a new start.