The country is a kingdom, a constitutional monarchy with King Bhumibol Adulyadej, the ninth king of the House of Chakri, who has reigned since 1946, making him the world's longest-serving current head of state and the longest-reigning monarch in Thai history. The king is officially titled Head of State, the Head of the Armed Forces, an Upholder of the Buddhist religion, and the Defender of all Faiths.