A day of formal celebrations will mark The Queen's 80th and The Duke of Edinburgh's 85th birthdays.
Her Majesty and His Royal Highness will attend a National Service of Thanksgiving at St Paul's Cathedral to celebrate The Queen's 80th birthday and The Duke of Edinburgh's 85th birthday.
Following the service, they will undertake a short walkabout in St Paul's Churchyard before attending a lunch at Mansion House at which The Queen will give a speech.
In the evening, the Massed Bands of The Royal Marines will perform a Beating Retreat on Horse Guards in celebration of The Duke of Edinburgh's 85th birthday.
The Service of Thanksgiving will begin at 11.15am. The Queen and The Duke of Edinburgh will attend, accompanied by 42 members of the Royal Family. Also present will be the Prime Minister, leaders of the Opposition, Government Ministers, Governor-Generals, Diplomats and leaders of Faith communities, along with 2,300 invited guests including 100 members of the general public drawn from a ballot.
42 members of the family means it's going to be an even bigger turnout that the thanksgiving service at St. Georges.