Born in the Sengoku or Warring States period (1467-1603) into the li family who lived in the Totomi province of Japan. She is most likely the only woman to rule as head of a clan during the Warring States period. She became lord after her father, Ii Naomori, died at the battle of Okehazama and his heir reportedly died in scandal. Her family also became vassals to the Imagawa clan after her father had been defeated in battle by Imagawa Yoshimoto.
After her father passed away Naotara's uncle, Naomitsu tried to marry her to his son, Naochika so he could inherit the clan but he was secretly plotting a rebellion against the Imagawa. Rebellion was reported by retainers of the Imagawa and Naomitsu and Naochika where ordered to commit "seppuku", Naomitsu died but Naochika was rescued by a Buddhist monk by the name of Nankei, who whisked him away to Shinano. While Naochika was in exile Naotara became a nun. Ten years later Naochika returned with a woman he had married while in exile and ruled the clan for a short time before it was discovered that he too was plotting a rebellion against the Imagawa and was killed by Imagawa Ujizane in 1560. It was after this that Naotara became head of the Ii clan. She went on to fight in many battles alongside the Tokugawa.
Naotara also adopted Naomasa Ii, Naochika's son; who became a loyal vassal of Ieyasu and one of the Four Guardian Kings of Tokugawa. However she was allegedly given the title "female landlord" instead of the formal title of daimyo (clan lord). She died September 12, 1582 and was succeeded by Ii Naomasa, her adopted son.
Footnotes
The battle of Okehazama (May-June 1560, Kyoto) was Oda Nobunaga's infamous battle where he utterly destroys the Imagawa army in a single battle. It displays Nobunaga's strategic intelligence because he defeats the massive Imagawa army with his much smaller forces. It should also be noted it was actually a three way battle between the Oda, Imagawa and Tokugawa armies.
Ieyasu Tokugawa is the founder of the Tokugawa clan. He is recognized today as one of three unifiers of Japan after Oda Nobunaga and Hideyoshi Toyotomi. He is best known for founding the Tokugawa shogunate, the last military regime of it's kind in Japanese history.
Four Guardian Kings of Tokugawa- four powerful generals who contributed greatly to Ieyasu's war efforts. Their name comes from the Four Heavenly Kings in Buddhism. It is not known if the title was fictional but it has been romanticized in paintings and books during the Edo period.
Shinano is a town in Nagano prefecture