Kingdom of Cambodia Preăh Réachéanachâk Kâmpŭchéa Flag Royal Arms Motto: Nation , Religion , King Anthem: Nokor Reach "Majestic Kingdom" Location of Cambodia ( green ) in ASEAN ( dark grey ) — [ Legend ] Capital (and largest city) Phnom Penh 11°33′N 104°55′E Official language(s) Khmer Official script Khmer script Demonym Khmer or Cambodian Government Unitary parliamentary democracy and Constitutional monarchy - King Norodom Sihamoni - Prime Minister Hun Sen ( CPP ) - Senate President Chea Sim ( CPP ) - President of National Assembly Heng Samrin ( CPP ) Legislature Parliament - Upper House Senate - Lower House National Assembly Formation - Funan Kingdom 68 - Chenla Kingdom 550 - Khmer Empire 802 - ...