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.
Government of Japan
The Government runs under the framework established by the Constitution of Japan, adopted in 1947. It is a unitary state, containing forty-seven administrative divisions, with the Emperor as its head of state. His role is ceremonial and he has no powers related to Government. Instead, it is the Cabinet, comprising the Ministers of State and the Prime Minister, that directs and controls the Government. The Cabinet is the source of power of the Executive branch, and is formed by the Prime Minister, who is the head of government. He or she is designated by the National Diet and appointed to office by the Emperor.