Her Majesty the Queen will celebrate 60 years on the throne with an anniversary service at Westminster Abbey today.
The Monarch, who spent the official anniversary on Sunday at Windsor Castle, will be joined at the abbey by 2,000 supporters.
Among them will be her immediate family including her husband the Duke of Edinburgh, Prince Charles and the Duchess of Cornwall, Prince Harry, Prince William and his heavily pregnant wife, Kate.
There are more celebrations planned for July, with a four-day Coronation festival lined up at Buckingham Palace.
But what time is today's service, who has been invited and what will it involve? We've got all the details you need to know.
What time is the service?
The service of celebration will take place on Tuesday, June 4 and is due to start at 11am with guests to be seated by 10am.
Before the service the Ampulla and Crown of St Edward will be brought from the Tower of London and placed on the High Altar.
Where is the service?
The service will take place at Westminster Abbey, the same venue where Her Majesty, 87, was crowned Queen 60 years ago.
The Queen succeeded King George VI on February 6 1952 when she was 25 years old, but it was not until 16 months later, on June 2 1953, that the young Queen was crowned at Westminster Abbey.
Thousands took to the streets despite the rainy weather to see the Queen’s procession and an estimated 27 million Britons watched the religious ceremony on black and white TV sets.
Who will be attending?
The anniversary service will be more low key than the Coronation 60 years ago, when 8,200 guests were present at the Abbey.
A guest list of 2,000 people has been invited to today's service and includes dignatries from across the UK, religious represetatives from churches from England, Northern Ireland, Scotland and Wales and of course the Queen's immediate and extended family.
The Duke of Edinburgh will be by the Queen's side for the duration of the ceremony and Her Majesty will be supported by her sons and daughter, grandchildren, nieces and nephews.
The Prime Minister David Cameron will attend the service with his wife Samantha, as will the Arch Bishop of Canterbury and the Mayor of Westminster.
What will the lead up to the service be like?
Prior to the Queen's arrival at the service the bells of the Abbey Church will ring, welcoming guests to the Abbey.
Inside, Organ Scholar Peter Holder will play a selection of music including Festal March by William Lloyd Webber, Prelude and Fugue in E flat BWV 552 by Johann Sebastian Bach, Water Music Suite No 3 in G HWV 350 by George Frideric Handel and Crown Imperial by William Walton and Herbert Murrill .
The assistant organist, Martin Ford, will play Allein Gott in der Hoeh sei Ehr BWV 662 by Johann Sebastian Bach, Rhosymedre from Three Preludes, founded on Welsh Hymn Tunes by Ralph Vaughan Williams and Prelude and Fugue in G Op 37 no 2 by Felix Mendelssohn.
The Lord Mayor of Westminster and consort will be welcomed into the Abbey at the Great West Door by the Dean and Chapter of Westminster and will be shown to their seats prior to a procession of religious representatives from churches in England, Northern Ireland, Scotland and Wales,.
Next to arrive will be members of the royal family including the Duke of York, Princess Beatrice and Eugenie, the earl and Countess of Wessex and Zara and Mike Tindall, followed by the Duke and Duchess of Cambridge and Prince Harry.
A Detachment of The Queen's Body Guard of the Yeomen of the Guard and of Her Majesty's Body Guard of the Honourable Corps of Gentlemen at Arms will then enter the Abbey ready for the arrival of Prince Charles and Camilla followed by The Queen and Prince Philip.
What is planned for the service?
The service, which will be conducted by the Very Reverend Dr John Hall, Dean of Westminster, will begin with the choir and the Queen's Scholar's of Westminster School singing The Introit.
Dean of Westminster John Hall will then give the bidding, explaining to the purpose of the service before leading the congregation in prayer and the National Anthem.
Prime Minister David Cameron will then read a bible passage from the book of Kings.
At this point the anointing will take place, during which a flask of oil will be received by the Archbishop of Canterbury
and given to the Dean to place on the altar as he prays for the Queen.
His Excellency Kamalesh Sharma, The Commonwealth Secretary-General, will then read a bible passage form the book of Mark before the congregation are asked to stand and sing the hymn, All People that on Earth do Dwell.
All will be seated for the Archbishop of Canterbury to give the address. The choir will then sing the anthem original sung at the Coronation in 1953.
Representatives from churches across Great Britain will then say prayers in celebration of the Queen, concluding with the Lord's prayer.
Actress Claire Skinner, of BBC sitcom Outbumbered will then read a poem specially written for the anniversary by Poet Laureate Carol Ann Duffy.
More prayers and a hymn are followed by a final blessing by the Dean, before the Queen and other members of the Royal family leave the service.
Who else is involved?
The bells of the Abbey Church will be rung by the Westminster Abbey Company of Ringers.
The service will be sung by the Choir of Westminster Abbey and the Choir of Her Majesty's Chapel Royal, St James's Palace, who will be conducted by the Abbey's Organist and Master of the Choristers, James O'Donnell.
The Fanfare Trumpeters of the Band of the Welsh Guards will also play, directed by Lieutenant Colonel Stephen Barnwell, and the organist for the day will be Martin Ford.
At 2.30 pm the Westminster Abbey Company of Ringers, conducted by David Hilling, will ring a Coronation Sixtieth Anniversary celebratory peal of London Surprise Royal comprising 5,060 changes.
How can I watch the service?
The BBC will be showing televised coverage of the service and lead up to the event from 10am.
David Dimbleby and Sophie Raworth will present BBC1 coverage, which will also include interviews with people who were present at the original ceremony in 1953.
The celebrations will also be streamed live on Radio 4 from 10.55am will commentary from Nicholas Witchell.
Highlights from the service will be shown on BB2 at 7pm.