Members of the Royal Family support The Queen in her many State and national duties, as well as carrying out important work in the areas of public and charitable service, and helping to strengthen national unity and stability.
Those who undertake official duties are members of The Queen's close family: her children, grandchildren and their spouses, and The Queen's cousins (the children of King George VI's brothers) and their spouses.
Every year the Royal Family as a whole carries out over 2,000 official engagements throughout the UK and worldwide.
These engagements may include official State responsibilities. Members of the Royal Family often carry out official duties in the UK and abroad where The Queen cannot be present in person. The Prince of Wales and The Princess Royal, for example, may present members of the public with their honours at an Investiture.
When official events such as receptions, State banquets and garden parties are held, the Royal Family supports The Queen in making her guests welcome.
Members of the Royal Family also often represent The Queen and the nation in Commonwealth or other countries, at events such as State funerals or national festivities, or through longer visits to strengthen Britain's diplomatic and economic relations.
The Royal Family also plays an important role in supporting and encouraging the public and charity sectors. About 3,000 organisations list a member of the Royal Family as patron or president.
The huge range of these organisations - covering every subject from education to the environment, hospitals to housing - allows members of the Royal Family to meet people from a wide spectrum of national and local life, and to understand their interests, problems and concerns.
2,000: the number of official engagements carried out by the Royal Family each year in the UK and overseas.
70,000: the number of people entertained each year to dinners, lunches, receptions and garden parties at the Royal residences.
100,000: the number of letters received and answered each year by the Royal Family.
Some members of the Royal Family have also established their own charities - for example, The Prince's Trust, The Duke of Edinburgh's Award Scheme and The Princess Royal Trust for Carers, a charity which provides advice and support for people acting as carers.
The Royal Family also plays an important role in recognising and supporting the work of the Armed Services. Members of the Royal Family have official relationships with many units of the Forces, paying regular visits to soldiers, sailors and airmen serving at home and abroad.
Finally, the Royal Family as a whole plays a role in strengthening national unity. Members of the Royal Family are able to recognise and participate in community and local events in every part of the UK, from the opening of new buildings to celebrations or acts of commemoration.
The Queen working by herself would be unable to attend every engagement to which she is invited. Members of the Royal Family can undertake local or specialist engagements which would otherwise have to be declined.