A rear admiral at the time of the attack on Pearl Harbor, Chester W. Nimitz was promoted directly to admiral and ordered to replace Admiral Husband Kimmel as Commander-in-Chief of the US Pacific Fleet. On March 24, 1942, his responsibilities were expanded to include the role of Commander-in-Chief, Pacific Ocean Areas which gave him control of all Allied forces in the central Pacific. From his headquarters, he directed the successful Battles of the Coral Sea and Midway before shifting Allied forces to the offensive with a campaign through the Solomons and island-hopping across the Pacific towards Japan. Nimitz signed for the United States during the Japanese surrender aboard USS Missouri on September 2, 1945.
Commander-in-Chief of the Japanese Combined Fleet, Admiral Isoroku Yamamoto initially opposed going to war. An early convert to the power of naval aviation, he cautiously advised the Japanese government that he anticipated success for no more than six months to a year, after which nothing was guaranteed. With war inevitable, he began planning for a quick first strike to be followed by an offensive, decisive battle. Executing the stunning attack on Pearl Harbor on December 7, 1941, his fleet scored victories across the Pacific as it overwhelmed the Allies. Blocked at the Coral Sea and defeated at Midway, Yamamoto moved into the Solomons. During the campaign he was killed when his plane was shot down by Allied fighters in April 1943.
A highly decorated officer during World War I, Admiral Andrew Cunningham quickly moved through the ranks and was named Commander-in-Chief of the Royal Navy's Mediterranean Fleet in June 1939. With the fall of France in June 1940, he negotiated the internment of the French squadron at Alexandria before taking the war to the Italians. In November 1940, aircraft from his carriers conducted a successful night raid on the Italian fleet at Taranto and the following March defeated them at Cape Matapan. After aiding in the evacuation of Crete, Cunningham led the naval elements of the North Africa landings and the invasions of Sicily and Italy. In October 1943, he was made First Sea Lord and Chief of the Naval Staff in London.
Commissioned in 1913, Karl Doenitz saw service in the various German navies prior to World War II. An experienced submarine officer, he rigorously trained his crews as well as worked to develop new tactics and designs. In command of the German u-boat fleet at the beginning of the war, he relentlessly attacked Allied shipping in the Atlantic and inflicted heavy casualties. Utilizing "wolf pack" tactics, his u-boats damaged the British economy and on several occasions threatened to knock them out of the war. Promoted to grand admiral and given full command of the Kriegsmarine in 1943, his u-boat campaign was ultimately thwarted by improving Allied technology and tactics. Named as Hitler's successor in 1945, he briefly ruled Germany.
Known as "Bull" to his men, Admiral William F. Halsey was Nimitz's leading commander at sea. Shifting his focus to naval aviation in the 1930s, he was selected to command the task force that launched the Doolittle Raid in April 1942. Missing Midway due to illness, he was made Commander South Pacific Forces and South Pacific Area and fought his way through the Solomons in late 1942 and 1943. Usually at the leading edge of the "island hopping" campaign, Halsey oversaw Allied naval forces in the critical Battle of Leyte Gulf in October 1944. Though his judgment during the battle is often questioned, he won a stunning victory. Known as a maverick that sailed his fleets through typhoons, he was present at the Japanese surrender.