If you mean the British Commonwealth then it is an association of nations consisting of the United Kingdom and several former British colonies that are now sovereign states but still pay allegiance to the British Crown, Queen Elizabeth. There are 53 members now. The Commonwealth promotes international peace and security, democracy, liberty and equal rights, as well as economic and social development. It opposes all forms of racial discrimination. It represents nearly two billion people almost a third of the worlds population from a wide range of faiths, races, cultures and traditions.
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The Commonwealth of Nations, normally referred to as the Commonwealth and previously as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states.