The Commonwealth is one of the world's oldest political association of states.
Its roots go back to the British Empire when some countries were ruled directly or indirectly by Britain. Some of these countries became self-governing while retaining Britain's monarch as Head of State. They formed the British Commonwealth of Nations.
In 1949 the association we know today – The Commonwealth – came into being.
In that year India became a republic but still wished to remain a member of the association. In response, leaders agreed that membership did not have to be based on allegiance to the British Crown. Commonwealth members were "free and equal members of the Commonwealth of Nations, freely co-operating in the pursuit of peace, liberty and progress" - The London Declaration 1949.
Since then, independent countries from Africa, the Americas, Asia, Europe and the Pacific have joined The Commonwealth.
The last two countries to join The Commonwealth - Rwanda and Mozambique - have no historical ties to the British Empire.