大化改新
About twenty years after the deaths of Shōtoku Taishi (in 622), Soga no Umako (in 626), and Empress Suiko (in 628), court intrigues over succession led to a palace coup in 645 against the Soga clan's monopolized control of the government. The revolt was led by Prince Naka no Ōe and Nakatomi no Kamatari, who seized control of the court from the Soga family and introduced the Taika Reform. The Japanese era corresponding to the years 645–649 was thus named , meaning "great change" in reference to the Reform. The revolt leading to the Taika Reform is commonly called the Isshi Incident, referring to the Chinese zodiac year in which the coup took place, 645.