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.
Line of succession to the Japanese throne
Before September 2006, there was a potential succession crisis since no male child had been born into the imperial family since Prince Akishino in 1965. Following the birth of Princess Aiko, there was significant public debate about amending the Imperial House Law to allow female descendants of an emperor and their descendants to succeed to the throne. In January 2005, Prime Minister Junichiro Koizumi appointed a special panel of judges, university professors, and civil servants to study changes to the Imperial House Law and to make recommendations to the government.