Born in Nagaoka, Niigata Prefecture in 1884, Isoroku Yamamoto was the son of a former samurai. After learning English after six tears at Nagaoka Middle School, he took the national entrance examination required before entering the Imperial Naval Academy and passed the test by placing the second highest nationwide. Yamamoto entered the academy in 1901, studied English, and made naval gunnery his concentrated area of study. He graduated from the academy in November 1904 ranked seventh out of a class of 191 with his commission as an Ensign.
After various successful naval assignments, he rose to the rank of Lieutenant Commander in 1915 and later married on August 31, 1918. He went on a two-year assignment to the United States from April 1919 through the summer of 1921 to study English and petroleum resources at Harvard University. While at Harvard, he became intensely interested in naval aviation. it was during his time among the Americans where he developed a deep-felt appreciation for American culture so sorely lacking among his countrymen at home.
After returning from the United States, he commanded several ships and served on the Japanese delegations to both London Naval Treaty Conferences. Yamamoto came closer to the centers of power in the Japanese government and became an avid advocate for naval aviation. He achieved his promotion to Rear Admiral before going to the first London conference in November 1930 and rose rapidly to the exalted rank of Vice Admiral, the highest rank in the Imperial Japanese Navy, in 1934. Yamamoto became the Navy Minister in December 1936 and strongly opposed the Army’s policy of war with China. He replaced Vice Admiral Zengo Yoshida as the Combined Fleet’s commander-in-chief on August 30, 1939.
It was at that time that war with the United States loomed in the immediate future. When he became the commander of Combined Fleet, in November 1940, Yamamoto rose to a four-star admiral. After noticing the successful British attack on the Italian battleships at Taranto, he conceived the idea of a surprise attack on the American naval base at Pearl Harbor. As we all know, his attack on the Hawaiian Islands was an outstanding tactical success and launched his country into war against the most powerful foe it had ever faced.
Flushed with his early successes in the Pacific, he was the architect for the Combined Fleet’s operations to capture Port Moresby, New Guinea (Battle of the Coral Sea – May 1942) and later Midway Island (Battle of Midway – June 1942). In both cases, he followed the Japanese Navy’s long-standing desire to engage their enemy in an all-out, winner-take-all naval battle and win the war with one sweeping stroke. The Imperial Japanese Navy had a tactical success at Coral Sea where it sank the American carrier Lexington and heavily damaged Yorktown. However, the Japanese strategically failed when they did not capture Port Moresby.
But Midway was another story. The Americans had broken the Japanese Navy’s JN-25 code that allowed Admiral Nimitz to send his three carriers – Enterprise, Hornet, and Yorktown – to steam to a spot northeast of Midway before the Japanese fleet arrived, lay in wait, and spring their deadly trap. The Combined Fleet suffered a devastating, total defeat at Midway when American carrier aircraft surprised Vice Admiral Nagumo and sank four Japanese fleet carriers – the Akagi, Soryu, Kaga, and Hiryu.
For the first time, Yamamoto felt the sting of defeat in a way he had never experienced before. Nonetheless, it was his duty to continue the war against the Americans despite any misgivings he might have secretly held the Japanese could never win.
Yamamoto had moved the Combined Fleet to new headquarters to the island of Truk in the Carolines, a collection of islands in the central Pacific and a former German possession the Japanese occupied since the end of World War I. It had a fine, deep harbor that could the largest ships in the Japanese Navy. From that advanced base, he commanded the numerous attempts to reinforce the Japanese soldiers on Guadalcanal and New Guinea. The results of these efforts, particularly the running of the Tokyo Express out of Rabaul, only resulted in marginal success.
His Combined Fleet’s ships met American naval forces in two great carrier battles during the battles for Guadalcanal – the Battle of the Eastern Solomons and the Battle of the Santa Cruz Islands – and inflicted some heavy damage on the American carriers. The Americans lost the Hornet at Santa Cruz and the Wasp to the torpedoes of a Japanese submarine. The Enterprise sustained heavy damage and had to retreat to Pearl Harbor for repairs. Meanwhile, Japanese cruisers and destroyers sank several American cruisers at the Battle of Savo Island, the Battle of Cape Esperance, the first night of the Naval Battle of Guadalcanal, and the Battle of Rennell Island.
The Japanese lost two battleships, the Hiei and Kirishima, one light carrier Ryujo and several cruisers and destroyers. While the Americans lost more ships, the Japanese suffered strategic defeats at each of the naval battles they fought against the Americans because they failed to land enough men and materiel to help their soldiers defeat the American Marines and soldiers on Guadalcanal. In addition, the losses among Japanese was even more appalling.
The situation became so severe such that many Japanese soldiers almost starved to death. The Japanese had to abandon their attempts to retake Guadalcanal and concentrate their efforts against MacArthur on New Guinea. The last surviving Japanese soldier left Guadalcanal on February 8, 1942. The Americans had full control of Guadalcanal and its valuable airfields on the next day.
Although the Combined Fleet launched a large attack at Guadalcanal in early April, that attack again failed to force the Americans to leave. Fearing the men of his command needed a boost to their morale, Yamamoto wanted to visit some of his command’s bases. His staff began planning his trip but warned him it would be dangerous. As their encoded messages about Yamamoto’s trip went out over the airwaves, American code breakers, who had broken the latest version of the Japanese naval codes, deciphered them and discovered his plans.
Admiral Nimitz asked his superiors for permission to assassinate the Japanese admiral. The reply to his request arrived from Washington with an emphatic approval. While Halsey toured his command, Rear Admiral John S. McCain assigned the task to intercept Yamamoto to the Army Air Force’s P-38 squadron on Guadalcanal. The American fighters left Guadalcanal on April 18, 1943, found the two Japanese bombers with Yamamoto flying in one of them, and shot down both of them. The Japanese admiral died along with the rest of his plane’s crew.
The Japanese had lost their most famous commander and kept the news of his death from the Japanese people for several months. The Americans did not immediately disclose they had killed the Japanese admiral because they did not want let the rest of the world know about their top-secret code breaking work. From this time forward, the Japanese had no choice but go on the defensive that continued until their surrender in Tokyo Bay in September 1945.