Born Isoroku Takano in Nagaoka in 1884, his first name translates from the old Japanese as the number 56, the age his schoolmaster father was when his son was born.
He later changed his second name after he was adopted by the Yamamoto family which lacked a suitable male heir to continue their family name.
Yamamoto graduated from the Imperial Japanese Naval Academy in 1904 and served in the Russo-Japanese War that began that year and he was wounded at the Battle of Tsushima, losing two fingers from his left hand.
He returned to the Naval Staff College in 1914 and was promoted to Lieutenant Commander in 1916. Yamamoto continued his studies at Harvard University, was twice posted to Washington as a naval attaché and learned to speak English fluently.
Yamamoto gained his captaincy in 1923 and was part of the Japanese delegation visiting the U.S. Naval War College and it was at this point that he began his ultimately fateful interest in naval aviation.
He continued to grow in rank and influence, first as a rear admiral, then vice admiral, and in the late 1930s Yamamoto was vocal in his opposition of the invasion of Manchuria in 1937 and the tripartite pact with Germany and Italy to the extent that he was the subject of death threats by Japanese nationalists.
Ironically it was fear of assassination that persuaded Navy Minister Mitsumasa Yonai to move Yamamoto from his post on land to take command of the combined fleet.
Yamamoto‘s career should have ended in 1941 when Hideki Tōjō became prime minister. The two had opposed each other over the war with China and it was assumed that Yamamoto would be sidelined with command of the Yokosuka Naval Base, but he retained his post as Admiral thanks to his popularity within the fleet and closeness to the Imperial family.
As war approached, Yamamoto reorganised his forces, concentrating the six aircraft carriers into the First Air Fleet. For two decades, Japan had planned for a long war of attrition with America over control of the Pacific before a decisive battle was reached, but Yamamoto saw that this could not succeed against his opponent’s superior resources and argued that only a preemptive strike might bring the Americans to the negotiating table.
It was perhaps more in hope than in expectation that Yamamoto planned the strike on Pearl Harbour and the failure to deliver the note breaking off diplomatic relations prior to the attack only served to harden America’s resolve. But for the time being, it gave the Japanese navy free rein in the Pacific.
The events that followed are well documented elsewhere, but Yamamoto continued to be a personal target for America.
In April 1943 US naval intelligence intercepted details of an inspection tour planned by Yamamoto in the wake of Japan’s defeat at Guadalcanal and Franklin D Roosevelt ordered an attack on the admiral.
A squadron of Lockheed P-38 Lightning planes was sent to intercept America’s bogeyman over Bougainville and Yamamoto was killed by bullets long before his transport plane crashed into the jungle. The story of that attack is told in the contemporary newsreel below.