To mark Commonwealth day, The Queen will 'break' the Commonwealth Flag outside the Great West Door of Westminster Abbey.
It will be the largest, single raising of this flag in the history of the Commonwealth.
The Queen signed the Commonwealth's historic charter tonight despite still recovering from the symptoms of gastroenteritis.
Making her first official public appearance for more than a week she described the document as capturing "the core values and aspirations" of the family of nations, before putting her name to it.
The Queen was forced to miss the annual Commonwealth Day service this afternoon as she was still recovering.
But she looked well and in good spirits when she arrived at Marlborough House in central London, home of the Commonwealth, with the Duke of Edinburgh for the signing.
The Queen has made a brief speech at a Commonwealth Day reception in her first public appearance since leaving hospital last week.
1 As of 2012 there are 54 countries in the Commonwealth, containing about one quarter of the world's population.
2 The origins of the Commonwealth come from Britain's former Empire. Many of the members of the Commonwealth were territories which had historically come under British rule at various times by settlement, conquest or cession.
3 The Queen is Queen of 16 the 54 Commonwealth member countries, all of them fully independent. She is represented by a Governor-General in all Realms except the UK.
4 Commonwealth Day, marked on the second Monday in March, is the annual celebration of the Commonwealth. The day was chosen as one when all Commonwealth children would be in school.
The Duke of Edinburgh has arrived at Westminster Abbey for a Commonwealth Service.
Buckingham Palace confirmed earlier that the Queen would not attend due to her continuing recovery from her recent illness.
However, Her Majesty is due to attend a reception this evening at the palace.
The Queen will not attend the Commonwealth Day service at Westminster Abbey today as she continues to recover following her recent illness, Buckingham Palace said today.
The Queen is to sign a new charter backing equal rights for women and gay people in every Commonwealth nation.
In a special ceremony to mark Commonwealth Day, she will endorse the document which includes the core values - from human rights to the rule of law - that leaders have committed to upholding.
In a pre-recorded speech to be broadcast today, the monarch will say the values of the new charter have "special emphasis" on including everyone in striving for a better future.
Read the full text and listen to the speech here:
The Queen will sign the new Commonwealth Charter in an event on Monday after it received the support of every Commonwealth nation.
According to the Mail on Sunday, the charter which backs equal rights for women and gay people says:
The Government is introducing new legislation ending discrimination against women in the line of succession to the British throne.
The measure will mean that the Duke and Duchess of Cambridge's first baby can succeed to the throne, regardless of whether the child is a girl or a boy.
The Queen is set to sign a new charter backing equal rights for women and gay people in her capacity as head of the Commonwealth, a Buckingham Palace spokesman has confirmed.
The Mail on Sunday quoted one Royal Household source as saying: "The Queen takes her Commonwealth role very seriously. She has discussed the charter in detail with her advisers and understands it in full."