Taika (大化) was a Japanese era name (年号, nengō) during the reign of Kōtoku.
This period spanned the years from August 645 through February 650.
[2] In 645, also known as Taika 1 (大化元年), the new era name was created to mark the beginning of the reign of the emperor Kōtoku.
[1] In Japan, this was the first nengō, derived from the Chinese system of eras (nianhao);[2] although some scholarly doubt has been cast on the authenticity of Taika and Hakuchi as historically legitimate era names.
[3] The system of Japanese era names was not the same as Imperial reign dates.