Wu Taibo

 Early in Japan`s history it was suggested that the first Emperor of Japan was or descended from Taibo of Wu. 

Who was he?

According to sources Taibo was the founder of the state of Wu in China around 1150 BCE. He was the eldest son of King Tai of Zhou and the rest of his story is surrounded with myth and legend. He developed irrigation, agriculture and dug the Taibo river (today called Bodu) 

Sometime between 722 and 481 BC Taibo left his country in the hands of his brother and went south to the barbarian lands. There he civilized them, bringing them culture. For his efforts they made him king. Later Japanese historians were able to draw many parallels to Jinmu and the founding of Japan.

Why is he important to Japan?

In the 14th century a scholar Chugan Engetsu took up the theory of Wu Taibo when he was writing his national history but his treaty was burned expressing that the idea was not accepted by the public. He came at a time when Japan was in chaos looking for a strong myth to connect it with the wider world.

In the late 16th century a Zen scholar by the name of Hayashi Razen (1583 - 1657) began a major study of the Nihon Shoki and Kojiki in 1644 as a means to legitimize the Tokugawa bakufu. He was a rationalist and serious Confucian scholar and as such hated stories of the gods. He didn`t trust what he couldn`t confirm with his own eyes. So he chose to set the founding of Japan by a famous Chinese man Wu Taibo. This moved the fate of Japan from the Gods directly to man, and a Chinese man. During his scholarship Chinese learning was respected above all and he would even write his histories in Chinese.

Nowhere is this information found in the Nihon Shoki or Kojiki which were the official chronicles of the Japanese history of the day. Jinmu is mentioned but only in a minor role in the beginning tied to the age of the Gods. 

So did he found Japan?

Probably not. However some of the earilest rice farmers in Japan most likely came from China 2000 years ago in what is known as the Yayoi period with DNA results connecting the Yangtze area with Yayoi era remains. It wouldn`t be a stretch for the farmers to bring across their culture and stories which would mix in with native Japanese ones from the Jomon era people. 

By the 18th century Chinese learning had gone out of fashion along with the idea of Japan being founded by Taibo. Western learning was becoming more popular and with it the idea of a powerful founder took the floor. In Jinmu they could bring national identity and create a stronger state with the hometown hero and not the man from a different country.

Sources: 

The Japan Times article, March 19, 1999 "Yayoi linked to Yangtze area. DNA tests reveal similiarities to early wet-rice farmers." Writer (unknown at this time)

Japanese Historians and the National Myths, 1600-1945 by John S. Brownlee

Founding Myths of the Japanese State: The Changing Perception of China and its Influence on Early Modern Japanese Identity. By David Weiss