Who, according to legend, is the first emperor of Japan?

Emperor Jimmu was the first Emperor of Japan, according to legend. His accession is traditionally dated as 660 BC. According to Japanese mythology, he is a descendant of the sun goddess Amaterasu, through her grandson Ninigi, as well as a descendant of the storm god Susanoo. He launched a military expedition from Hyuga near the Seto Inland Sea, captured Yamato, and established this as his center of power. In modern Japan, Jimmu's accession is marked as National Foundation Day on February 11.