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-Shirakawa
Emperor Go-Shirakawa (後白河天皇 "Go-Shirakawa-tennō") (October 18, 1127 – April 26, 1192) was the 77th emperor of Japan, according to the traditional order of succession. His reign spanned the years from 1155 through 1158, while he remained effectively in power for almost 37 years.