There are 54 states in the Commonwealth, 33 republics, 16 countries with Queen Elizabeth as their head of State and five with their own monarchies.

The organisation originated in parallel with the dismantlement of the British Empire, and Ireland (or the Irish Free State as it then was) was one of the first members.

In 1926 at the Imperial Conference, six dominions (Australia, Canada, the Irish Free State, Newfoundland, New Zealand and South Africa) were described as "autonomous communities within the British Empire, equal in status, in no way subordinate one to another in any aspect of their domestic or external affairs, though united by a common allegiance to the Crown and freely associated as Members of the British Commonwealth of Nations".

Ireland left in 1949 upon declaring itself a republic. But very soon after, a special dispensation was granted to India to remain a member even though it, too, was a republic.

This is seen as the point at which the modern Commonwealth came into being, an organisation that likes to think of itself as having neither centre nor periphery and one in which all members, Britain included, are equal.

It was at this time that the organisation stopped calling itself the British Commonwealth.

While Queen Elizabeth remains the head of the Commonwealth, the position is deemed to be vested in her rather than in the crown, a rather British constitutional solution to a very British problem.

Commonwealth heads of government meet every other year, usually in a major city of a member-state, and discuss matters of mutual interest and co-operation such as health, education, law, women's affairs, agriculture and youth affairs.

Meetings are an opportunity for politicians, academics, economists and non-governmental workers to network. Commonwealth Games are held every four years.

Since the dismantlement of apartheid in South Africa, the single issue which bound many member-states to the organisation because it provided a stage from which they could attack the whites-only regime, the Commonwealth has been searching for a role.

Increasingly, human rights and the promotion of democracy have come to the fore. In 1991 the organisation dedicated itself to working for these, as well as the rule of law, the independence of the judiciary and honest government, ideals which do not sit comfortably with the rulers of all the member-states.

The organisation is run by a secretariat in London, shortly to be joined as deputy director-general by Dame Veronica Sutherland, Britain's outgoing ambassador to Ireland.

Next April the Commonwealth will celebrate the 50th anniversary of its present incarnation, a moment which its supporters would dearly love to see marked by Ireland's return to the fold.

The members of the Commonwealth are: Antigua and Barbuda, Australia, The Bahamas, Bangladesh, Barbados, Belize, Botswana, Britain, Brunei, Cameroon, Canada, Cyprus, Dominica, Fiji, The Gambia, Ghana, Grenada, Guyana, India, Jamaica, Kenya, Kiribati, Lesotho, Malawi, Malaysia, Maldives, Malta, Mauritius, Mozambique (the only non-former British colony), Namibia, Nauru, New Zealand, Nigeria, Pakistan, Papua New Guinea, St Kitts and Nevis, St Lucia, St Vincent and the Grenadines, Samoa, Seychelles, Sierra Leone, Singapore, Solomon Islands, South Africa, Sri Lanka, Swaziland, Tanzania, Tonga, Trinidad, Tuvalu, Uganda, Vanuatu, Zambia and Zimbabwe.