The nation is set to enjoy a weekend of celebrations to mark the Queen's Diamond Jubilee - with fingers crossed that the weather stays dry.
The four-day Bank Holiday gives the country the opportunity to gather together to mark the Queen's historic 60-year reign.
Up to a million people are expected to line the banks of the River Thames and nearby open spaces to watch a majestic 1,000-strong flotilla sail through London on Sunday.
And stars like Stevie Wonder, Sir Paul McCartney and Sir Elton John will perform at a concert the following day in honour of the longest reigning monarch since Queen Victoria.
Almost six million Britons plan to throw a Jubilee party this weekend, according to a study.
A special visual tribute will see Diamond Jubilee Beacons light up the night sky across the UK on Monday, with more than 4,000 expected to be lit here and in the Commonwealth.
A St Paul's Cathedral service of thanksgiving will be the highlight of Tuesday, ending with the Queen appearing on Buckingham Palace's balcony to acknowledge the tens of thousands expected to fill The Mall.
Prime Minister David Cameron, the Duke of Edinburgh, Prince of Wales and other senior royals will join prominent individuals from the UK and abroad at many of the events.
Interviewed by Parliament's The House magazine ahead of the celebrations, Mr Cameron said: "I owe the Queen a huge debt for the wisdom she has shown me over the past couple of years. Six decades of service have given her an acute sense of what matters, what is permanent, and what is in Britain's best interests.
"As her previous prime ministers have found, those insights are extremely useful. She is quite simply a remarkable person and a towering figure in our history. Long may she reign."
The celebrations begin on tomorrow with the Queen enjoying her traditional outing to the Epsom Derby.
As a passionate horse breeder, she rarely misses the famous race meeting and will take her usual place in the Royal Box to study the form - but she does not bet.
The turf of the racecourse will be replaced by the waters of the Thames on Sunday when she joins Charles, Camilla, the Duke and Duchess of Cambridge and Prince Harry on the Royal Barge for the River Pageant.
Lavishly decorated with replica carvings and sporting a majestic red, gold and purple colour scheme, the vessel will be the centre of the flotilla featuring every conceivable vessel from kayaks and steam paddlers to rowing boats and skiffs.
Neighbourliness will be the catchword when hundreds of Big Jubilee Lunches are held, with many people expected to stage them outdoors as street parties that afternoon.
In the shadow of Buckingham Palace, the concert in honour of the Queen will see Stevie Wonder joined by other names like Dame Shirley Bassey, Cheryl Cole, Grace Jones, Sir Tom Jones, Annie Lennox, will.i.am and Robbie Williams.
The Queen will be invited on to the stage on Monday night to light the national, and last, Jubilee Beacon by dropping a diamond-shaped crystal into a pod.
During the final day of celebrations, the Archbishop of Canterbury, Dr Rowan Williams, is expected to pay tribute to the monarch in his sermon at the St Paul's Cathedral service of thanksgiving.
Later, events will be held in the City and Westminster before the senior royals take a carriage procession through the streets of London back to Buckingham Palace where they will watch the fly-past.
A Dakota will be flanked by two King Air aircraft, and a Lancaster, Spitfires and a Hurricane from the Battle of Britain Memorial Flight, and they will be followed by a display by the Red Arrows.
The recent heatwave is not expected to last over the weekend with showers expected to dampen the celebrations at some point, but the River Pageant is likely to be dry.