The current British monarch Elizabeth II is the head of state of Britain, the Commonwealth and 15 member countries, and also the supreme leader of the Anglican Church. Her full name is "by the grace of God, the King of England and its territory, Elizabeth II, the head of the Commonwealth, the guardian of faith" (by the grace of God, the queen of the United Kingdom of Great Britain and Northern Ireland and other fields and territories, the head of the Commonwealth, the guardian of faith). She ascended the throne on February 6th, 1952, and was the second longest-serving head of state (after King Bhumibol adulyadej of Thailand who reigned in 1946). About 654.38+25 million people live in the country where she is the head of state.

Among 15 Commonwealth countries that recognize Elizabeth II as the head of state, her status as head of state has been recognized by the Constitution. These countries were once British colonies or dominions. According to the earlier Westminster Act, which was used to distinguish British colonies from British dominions, "any law that may change the succession to the throne and royal titles must be approved by the British Parliament and all dominion parliaments before it can be implemented." After independence, the 15 countries that continue to recognize the queen (or king) as the head of state have actually achieved a status similar to this kind of autonomous territory, although according to the Westminster Act, these countries are not autonomous territories and have no right to decide on their own to change their inheritance methods. After the death of Elizabeth II, her descendants will become their heads of state according to the constitutions of these countries, not according to the principle of inheritance.