Born in 1712 as the eldest son of the 8th shogun Tokugawa Yoshimune. He suffered from what is believed to have been cerebral palsy, making his speech extremely difficult to understand. Yoshimune considered naming his second son Munetake as heir but upheld the principle of primogeniture and chose Ieshige. He became the 9th shogun in 1745. The only person who could understand his speech was Ooka Tadamitsu, who had served him since childhood and was appointed chamberlain to convey Ieshige's will to the government. Tadamitsu is said to have served faithfully without abusing his power. In 1760, Ieshige abdicated in favor of his son Ieharu and died the following year at age 50.

Often dismissed as incompetent due to his speech impediment, but recent scholarship suggests he was actually intelligent with a good eye for talent. He may have made sound judgments conveyed through Tadamitsu.

A unique shogun who fulfilled his duties despite a severe speech impediment. His bond with Ooka Tadamitsu is being reappraised as a story of trust between a person with disability and his understanding companion. The novel 'Maimai Tsuburo' has recently brought renewed attention to his life.