Background of Yamato society and culture
Yamato, in the 7th century
A millennium earlier, the Japanese archipelago had been inhabited by the Jōmon people. In the centuries prior to the beginning of the Yamato period, elements of the Northeast Asian and Chinese civilizations had been introduced to the Japanese Archipelago in waves of migration. According to Kojiki, the oldest record of Japan, a Korean immigrant named Amenohiboko, prince of Silla came to Japan to serve the Japanese Emperor, and he lived in Tajima Province. His descendant is believed to be Tajimamori. Archaeological evidence indicates contacts between China, Korea, and Japan since prehistory of the Neolithic period, and its continuation also at least in the Kofun period.
The rice-growing, politically-fragmented Yayoi culture either evolved into the new Japanese culture characterized by the more centralized, patriarchal, militaristic Kofun period or came to be dominated and eventually overrun by Yamato society.
By this time, Japonic had also spread to the Ryukyu Islands such as Okinawa. The Ryukyuan languages and Japanese most likely diverged during this period.