Isoroku Yamamoto (山本 五十六, Yamamoto Isoroku; April 4, 1884 – April 18, 1943) was an admiral of the Imperial Japanese Navy (IJN) and the commander of the Combined Fleet during World War II. He commanded the fleet from 1939 until his death in 1943, overseeing the start of the Pacific War in 1941 and Japan's initial successes and defeats before his plane was shot down by U.S. fighter aircraft over New Guinea.
Yamamoto graduated from the Imperial Naval Academy in 1904 and served in the Russo-Japanese War, where he lost two fingers at the Battle of Tsushima. He later studied at Harvard University in the United States and was appointed naval attaché to the Japanese embassy in Washington. His experiences convinced him that naval power depended on access to oil and industrial capacity, and that Japan thus had little hope to defeat the U.S. in a war. He was one of the first naval leaders to conclude that naval aviation and aircraft carriers would play a decisive role in any future conflict.
In 1936, Yamamoto was appointed navy vice minister, and opposed Japan's alliance with Germany and Italy in the Tripartite Pact of 1940. In 1939, he was appointed commander-in-chief of the Combined Fleet, and was tasked with creating a strategy for war with the United States; Yamamoto favored a surprise attack, which was carried out at the start of the war with an attack on Pearl Harbor in December 1941.
In the early months of the war, the Japanese fleet scored a series of decisive naval victories. These gains were halted at the Battle of Midway in June 1942, in which four Japanese carriers were sunk. Yamamoto committed to the defense of the Solomon Islands in the Guadalcanal campaign, but was unable to prevent their capture. In April 1943, Yamamoto was killed after American code breakers intercepted his flight plans, enabling the United States Army Air Forces to shoot down his aircraft.
Yamamoto was born as Isoroku Takano (高野 五十六, Takano Isoroku) in Nagaoka, Niigata. His father, Sadayoshi Takano (高野 貞吉), had been an intermediate-rank samurai of the Nagaoka Domain. "Isoroku" is a Japanese term meaning "56"; the name referred to his father's age at Isoroku's birth.
Isoroku was the 6th son and 7th child of Sadayoshi. His mother was Sadayoshi's third wife. The three wives were sisters; the first two died young. It was common at the time for a widower to marry the younger sister of a wife who died.
In 1916, Isoroku was adopted into the Yamamoto family (another family of former Nagaoka samurai) and took the Yamamoto name. It was a common practice for samurai families lacking sons to adopt suitable young men in this fashion to carry on the family name, the rank and the income that went with it. Isoroku married Reiko Mihashi in 1918; they had two sons and two daughters.
Yamamoto graduated from the Imperial Japanese Naval Academy in 1904, ranking 11th in his class. He then subsequently served as a signalman on the armored cruiser Nisshin during the Russo-Japanese War. He was wounded at the Battle of Tsushima, suffering a wound "the size of a baby's head" on his thigh and losing his index and middle fingers on his left hand, in an explosion in the ship's forward turret. It appeared the explosion was not the result of Russian fire but of the gun itself exploding. He returned to the Naval Staff College in 1914, emerging as a lieutenant commander in 1916. In December 1919, he was promoted to commander.
Yamamoto was part of the Japanese Navy establishment, who were rivals of the more aggressive Army establishment, especially the officers of the Kwantung Army. He promoted a policy of a strong fleet to project force through gunboat diplomacy, rather than a fleet used primarily for the transport of invasion land forces, as some of his political opponents in the Army wanted. This stance led him to oppose the invasion of China. He also opposed war against the United States, partly because of his studies at Harvard University (1919–1921) and his two postings as a naval attaché in Washington, D.C., where he learned to speak fluent English. Yamamoto traveled extensively in the United States during his tour of duty there, where he studied American customs and business practices.
He was promoted to captain in 1923. On February 13, 1924, Captain Yamamoto was part of the Japanese delegation visiting the United States Naval War College. Later that year, he changed his specialty from gunnery to naval aviation. His first command was the cruiser Isuzu in 1928, followed by the aircraft carrier Akagi.
He participated in the London Naval Conference 1930 as a rear admiral and the London Naval Conference 1935 as a vice admiral, as the growing military influence on the government at the time deemed that a career military specialist needed to accompany the diplomats to the arms limitations talks. Yamamoto was a strong proponent of naval aviation and served as head of the Aeronautics Department, before accepting a post as commander of the First Carrier Division. Yamamoto opposed the Japanese invasion of northeast China in 1931, the subsequent full-scale land war with China in 1937, and the Tripartite Pact with Nazi Germany and Fascist Italy in 1940. As Deputy Navy Minister, he apologized to United States Ambassador Joseph C. Grew for the bombing of the gunboat USS Panay in December 1937. These issues made him a target of assassination threats by pro-war militarists.
Throughout 1938, many young army and naval officers began to speak publicly against Yamamoto and certain other Japanese admirals, such as Mitsumasa Yonai and Shigeyoshi Inoue, for their strong opposition to a tripartite pact with Nazi Germany and Fascist Italy, which the admirals saw as inimical to "Japan's natural interests". Yamamoto received a steady stream of hate mail and death threats from Japanese nationalists. His reaction to the prospect of death by assassination was passive and accepting. The admiral wrote:
To die for Emperor and Nation is the highest hope of a military man. After a brave hard fight the blossoms are scattered on the fighting field. But if a person wants to take a life instead, still the fighting man will go to eternity for Emperor and country. One man's life or death is a matter of no importance. All that matters is the Empire. As Confucius said, "They may crush cinnabar, yet they do not take away its color; one may burn a fragrant herb, yet it will not destroy the scent." They may destroy my body, yet they will not take away my will.
The Japanese Army, annoyed at Yamamoto's unflinching opposition to a Rome-Berlin-Tokyo treaty, dispatched military police to "guard" him, a ruse by the Army to keep an eye on him. He was later reassigned from the naval ministry to sea as the commander-in-chief of the Combined Fleet on August 30, 1939. This was done as one of the last acts of acting Navy Minister Mitsumasa Yonai, under Baron Hiranuma Kiichirō's short-lived administration. It was done partly to make it harder for assassins to target Yamamoto. Yonai was certain that if Yamamoto remained ashore, he would be killed before the year ended.
Yamamoto was promoted to admiral on November 15, 1940. That was in spite of the fact that when Hideki Tojo was appointed prime minister on October 18, 1941, many political observers thought that Yamamoto's career was essentially over. Tojo had been Yamamoto's opponent from the time when the latter served as Japan's deputy naval minister and Tojo was the prime mover behind Japan's takeover of Manchuria.
It was believed that Yamamoto would be appointed to command the Yokosuka Naval Base, "a nice safe demotion with a big house and no power at all". However, after a brief stint in the post, a new Japanese cabinet was announced, and Yamamoto found himself returned to his position of power despite his open conflict with Tojo and other members of the Army's oligarchy, who favored war with the European powers and the United States.
Two of the main reasons for Yamamoto's political survival were his immense popularity within the fleet, where he commanded the respect of his men and officers, and his close relations with the imperial family. He also had the acceptance of Japan's naval hierarchy: