Abe, 65, has been in office since 2012. He also served as prime minister for one year beginning in 2006, but left because of a corruption scandal. His longevity is noteworthy in a country that sees frequent turnover in its leadership.

(Photo: Japanese Prime Minister Shinzo Abe speaks during a ceremony at the Hiroshima Peace Memorial Park on Aug. 6 to mark the 75th anniversary of the U.S. atomic attack. Abe announced his resignation Thursday - Eugene Hoshiko/AP)