It is an international union of nations working together to promote a number of common values and goals, such as democracy, human rights, good governance, and the rule of law.
It originated with the 1931 Statute of Westminster, and its original members were the United Kingdom, Canada, Australia, New Zealand, South Africa, Newfoundland (which joined the Canadian Confederation in 1949) and the Irish Free State (which left the Commonwealth in 1949).
India, Pakistan and Ceylon (later Sri Lanka) joined the British Commonwealth – as it was then called - when they became independent in 1947.
The London Declaration of 1949 emphasized the Commonwealth's member states' independence from Britain by renaming it the Commonwealth of Nations and by recognising the British monarch's role only as Head of the Commonwealth.
This has allowed republics such as India and Pakistan, and countries with their own monarchies, to remain part of the Commonwealth without compromising their sovereignty.
Since the London Declaration the Commonwealth has grown through the decolonisation of the British Empire and, between 1957 and 1970, over 20 former Crown colonies joined the organisation as they gained their independence.
Most of the Commonwealth countries, reflecting their British influence, have adopted a Westminster-style form of parliamentary government, with elected legislatures, often with an upper and lower chamber; multi-party democratic elections; and responsible government by ministries drawn from the majority party and accountable to the elected legislature and its opposition parties.
Common values and co-operation
The values of the Commonwealth are reflected in the work of the Commonwealth Parliamentary Association (CPA), an organisation with branches in every Commonwealth nation.
The CPA aims to build co-operation and discussion between Commonwealth MPs and to promote good standards of parliamentary practice across the globe through frequent international conferences, workshops and meetings.
The Commonwealth of Nations, and the aspirations for parliamentary democracy and good governance promoted by the CPA, remain the most enduring and hopeful legacy of the disbanded British Empire.