The Jinshin War (壬申の乱, Jinshin no Ran) was a short civil war in Japan in the year 672. It was a fight about who should be the next emperor after Emperor Tenji died.
Before Emperor Tenji died, he gave power to his son Prince Ōtomo (later called Emperor Kōbun). But Tenji’s brother, Prince Ōama, also wanted to be emperor. He had more support from soldiers and powerful families.
Prince Ōama started a war to take the throne. The fighting lasted only a few weeks. Ōama’s army moved quickly and defeated Kōbun’s forces. Kōbun died during the war, possibly by suicide.
After winning, Prince Ōama became Emperor Tenmu. He made many changes to the government and helped make the emperor more powerful.