It is an organisation of 53 member states that are mostly former territories of the British Empire. It operates by intergovernmental consensus of the member states, organised through the Commonwealth Secretariat and non-governmental organisations, organised through the Commonwealth Foundation. Queen Elizabeth II is the Head of the Commonwealth and the monarch of 16 members of the Commonwealth, known as Commonwealth realms. Member states have no legal obligation to one another. Instead, they are united by language, history, culture and their shared values of democracy, free speech, human rights, and the rule of law. Every 2 years, member countries meet to discuss issues affecting the Commonwealth and the wider world at the Commonwealth Heads of Government Meeting (CHOGM). All members have an equal voice, regardless of size or economic stature. Some members treat resident citizens of other Commonwealth countries preferentially to citizens of non-Commonwealth countries. The first member to be admitted without having any link to the British Empire was Mozambique.