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.
Prime Minister of Japan
The is the head of government and chief executive of Japan. The Prime Minister is appointed by the Emperor of Japan after being designated by the National Diet and must enjoy the confidence of the House of Representatives to remain in office. He is the chairman of the Cabinet and appoints and dismisses the other Ministers of State. The literal translation of the Japanese name for the office is "Minister for the Comprehensive Administration of ("or" the Presidency over) the Cabinet".