The Queen was joined by members of the Royal Family for the annual Commonwealth Day Service at Westminster Abbey. The annual service is a celebration of the 54 member states: their differences, their common ground, what they have achieved together and what they hopes to achieve in the future.
The Queen has been Head of the Commonwealth since she acceeded to the throne in 1952, but pledged her life to the service of Commonwealth citizens years before she became Queen.
The organisation has grown far beyond its initial membership of eight nations in 1949.
The service - always held in the splendid surroundings of Westminster Abbey - comprises traditional hymns and readings alongside national song and dance performances and more modern acts. Often performers and speakers hail from Commonwealth countries or have grown up in the UK with Commonwealth heritage.
Heavyweight champion Anthony Joshua spoke of the happy mix of cultures which the Commonwealth can represent.
Her Majesty - who attended in her role as Head of the Commonwealth - was joined by other members of the Royal Family.
The Queen is supported in her work by working members of the Royal Family who often travel to the furthest corners of the Commonwealth to see projects in action. Nations are constantly working together on a huge variety of projects, from gender equality to the environment, the shipping trade to avoidable blindness.
The Queen's Commonwealth Day message emphasised the idea of using the Commonwealth nations' many differences as an advantage.