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.
Heisei period
In August 2016, Emperor Akihito gave a televised address to the nation, in which he expressed concern that his age would one day stop him from fulfilling his official duties. This was an implication of his wish to retire. The Japanese Diet passed a law in June 2017 to allow the throne to pass to Akihito's son, Naruhito. After meeting with members of the Imperial House Council, Prime Minister Shinzō Abe announced that 30 April 2019 would be the date set for Akihito's abdication. The Era of Naruhito's reign will begin the next day.