A constitutional monarchy is a governmental system in which the head of State is a king or a queen who reigns but do not rule. The country is namely reined by the sovereign, but virtually by His or Her Majesty's Government—a body of Ministers who are the leading members of whichever political parties the electorates has voted into office, and who are responsible to parliament. The rule of the monarchy is primarily to symbolize the tradition and unity of the British state.