Eisaku Sato (1901-1975) was a Japanese political leader who served as prime minister longer than anyone else in Japanese history. Under his leadership Japan gradually began to translate its immense economic strength into enhanced political power in the international environment.

Eisaku Sato was born on March 27, 1901, in Yamaguchi Prefecture into a family of samurai descent. His home province, Choshu, provided much of the leadership (including Sato's great-grandfather) in the movement that overthrew the Tokugawa shogunate in 1868 and established the new imperial government. During the first century after the Meiji restoration, Yamaguchi provided more premiers than any other prefecture.

Sato therefore grew up in an atmosphere highly charged with political concerns; his mother was reported to have impressed upon her sons a sense of obligation to serve the state. Sato's eldest brother, Ichiro, became a rear admiral, retiring just prior to World War II. Another older brother, Nobusuke Kishi...