Abstract: This article is dedicated to the establishment of precise chronology of the second quarter of the V century in the history of Ancient Japan, as back in the XIX century it was founded out that the reign time of the first Yamato emperors was excessively extended. The researchers were able to determine the proper chronology of the second half of the IV – beginning of the V century; but the precise chronology of the first half of the V century until the middle of the V century, when Japan borrowed the Chinese calendar Yuan Xi Lie, which gave the more precise chronology. The comparison of records of the Chinese dynasty stories about five wangs of Japan in the V century with the records about the Yamato emperors of the same period in Japanese sources, allowed ascertaining time of the reign of the aforementioned monarchs. The author determines the reason of distortion of the Yamato chronology of the second quarter of the V century in “Nihon Shoki”, founded on the cyclic indication of the Korean sources “Baekje Shinchan” that applied the inaccurate cycle, which is 26 years behind times. In restoring the authentic cyclic indicators, considering its shift back to 26 years, the author attempts to reconstruct the chronology of the second quarter of the V century within the accuracy of the year of reign, lunar month and day of event.

Abstract: In this article, data of Japanese sources on East campaign the sovereign Jimmu and the establishing of a Yamato dynasty and state in the Central Japan in comparison to results of archaeological researches of the ancient Japanese monuments of material culture of the late yayoi period and the early kofun period for the purpose of definition of chronology of the establishing of Yamato are analyzed. Also materials of the Korean chronicles for the purpose of detection of the indirect evidences allowing to date the time of foundation of Yamato state of are analyzed. Besides materials of Chinese dynastic histories about the establishing of the state in the Central Japan are provided.Results of archaeological researches allow to correct chronology of ancient Japan, and, on the basis of cyclic designations of a 60-year cycle from the ancient Japanese written sources, give the chance to offer the corrected datings of time of East campaign to Jimmu and his reigns as the first sovereign of Yamato.The main result of this research is the conclusion that, on the basis of results of archaeological researches and indirect evidences of the Korean sources, East campaign of Jimmu was carried out at the end of the III century AD (294-300), and foundation of Yamato dynasty and state occurred at the beginning of the IV century (in 301 AD). Sovereign Jimmu ruled during 16 years (301-316 AD).