It's called in the Asuka period from the second half in the 6th century to the beginning in the 8th century.
It is called the Asuka period from opening the base of the royal prerogative of Yamato in Asuka.
It is to have changed the country name to Japan from Wa ( Yamato ) in this period.
The end of sixth century
Sui unified China after an interval of 400 years.
Of the political power of East Asia countries centralized.
The early seventh century
701 years Taiho Code enacted(National Basic Code of the time)
710 years It transfered the capital to Heijokyo in Nara.
Even in Wa Suiko and its Oiumayato-o(Prince Shotoku),Minister of Soga no Umako was concentration of power is grave become a center.
From reflection of the first envoy to the Sui Dynasty dispatch, government reform was carried out.
But there was resistance of a powerful family and concentration of power didn't work.
Imoko Onono was dispatched in the second envoys to the Sui Dynasty.
The Taika Reformation of the mid-seventh century was one of the movement of the power centralization and showed constant progress.
Second half of the seventh century , power centralized began proceed rapidly.
Tenmu who won the Jinshin War is thorough power intensive , tried to deification of the Emperor.