Koken

Born: 718, Nara, Japan
Died: Aug 28, 770, Nara
Koken was the last empress to rule Japan until the 17th century; she twice occupied the throne (749-758; 764-770). There had been a number of female rulers before Koken, but the power achieved by the Buddhist monk Dokyo during her second reign caused the Council of Ministers to preclude female succession to the throne thereafter.
Koken was the daughter of the emperor Shomu; she ascended the throne in August 749, as the empress Koken, when her father abdicated. Nine years later she abdicated in favour of Prince Oi, who ruled as Emperor Junnin. In 761, she met Dokyo when he was lecturing at the imperial palace. Her attempts to promote the career of the priest, who was presumably her lover, brought him into conflict with Junnin’s favourite minister, the powerful Oshikatsu.
In 764, the conflict erupted into a civil war in which Oshikatsu was killed and Junnin was deposed. Koken then reascended the throne, ruling as the empress Shotoku. Although Dokyo attained virtual control of the government during her reign, his attempt to become emperor upon her death resulted in his banishment from the capital.