Japan was not called Japan at first. In ancient Japanese mythology, the Japanese called it "eight continents" and "eight island countries". According to the records in Hanshu and Houhanshu, Japan was called "Japan" or "Japan" in ancient China. In the 5th century A.D., after Japan's reunification, its national title was "Yamato". Because the ancient Japanese worshipped the sun god and regarded the sun as their totem. According to legend, at the beginning of the 7th century, Shoto Kutaishi of Japan wrote in a letter to Emperor Yang Di: "Where the sun comes from, the son of heaven goes at sunset", which is the embryonic form of Japanese country name. It was not until the second half of the 7th century that Japan sent Tang Shi to change the country name to "Japan", which means "the place where the sun rises", that it became the official country name of Japan. According to the Biography of the New Tang Dynasty in Japan, in the first year of Xianheng (670), Japan sent envoys to the Tang Dynasty. At this point, Japan has "learned a little bit about Xia Yan, hated its name and changed its name to Japan". The messenger said that he was famous for his recent appearance. "In addition, in Chinese," Fusang "and" Japan "are also nicknames for Japanese country names.
About 1 century, there were more than 100 small countries in Japan (some of them established diplomatic relations with the Eastern Han Dynasty). Later, these small countries gradually unified.
In the 4th century, Kansai established a relatively large country. It is said that the ancestors of the royal family finally unified them today. At that time, Japan included western Honshu, northern Kyushu and Shikoku.
Therefore, it will take a long time for this country to be unified. Therefore, it is difficult to make an accurate judgment on the exact date of the birth of Japan. According to Records of Historical Records and Records of Japan, the first emperor Emperor Jimmu was founded in 660 BC and acceded to the throne. The date of his accession to the throne is equivalent to 1 1 in the current Gregorian calendar, so this day is designated as the "founding day".