Records of heads of state
Officially, the current Emperor of Japan, Akihito is the 125th in line from the first emperor Jimmu, who is variously believed to have reigned in the 1st or 7th century BC. The earliest documentary evidence is only for the 29th emperor, Kinmei (AD 509–571); however, this is sufficient such that even the most conservative of estimates still places the Japanese imperial family as among the oldest lines in the world today.
Emperor Go-Daigo
Emperor Go-Daigo (後醍醐天皇 "Go-Daigo-tennō") (November 26, 1288 – September 19, 1339) was the 96th emperor of Japan, according to the traditional order of succession. He successfully overthrew the Kamakura shogunate in 1333 and established the short lived Kenmu Restoration to bring the Imperial House back into power. This was to be the last time the emperor had any power until the Meiji Restoration in 1868. The Kenmu restoration was in turn overthrown by Ashikaga Takauji in 1336, ushering in the Ashikaga shogunate, and split the imperial family into two opposing factions between the Ashikaga backed Northern Court situated in Kyoto and the Southern Court based in Yoshino led by Go-Daigo and his later successors.