National celebrations to mark the Queen's Diamond Jubilee have begun as the country gears up for a weekend of pomp and pageantry in honour of Her Majesty
Events staged in tribute to the Queen's 60-year reign will be held across the UK during the extended four-day Bank Holiday, with spectacular public activities planned for the capital.
The Royal Navy warship HMS Diamond signalled the start of the festivities in dramatic fashion by firing a 21-gun salute that boomed across Portsmouth Harbour.
Tributes have been paid to the Queen from two national figures - the Prime Minister and the Archbishop of Canterbury, Dr Rowan Williams - with both agreeing the importance of the country's head of state.
And a poll suggests a large majority of the UK public, 80% of those questioned for an Ipsos Mori Diamond Jubilee survey, want to remain a monarchy.
David Cameron, interviewed by Sky News, was asked whether he thought the Queen might step down one day in favour of her son the Prince of Wales.
He replied: I wouldn't anticipate that. What I see in Her Majesty is someone, in spite of the fact she's been on the throne for 60 years, in spite of the fact that her and Prince Philip are now relatively elderly, there is an extraordinary level of physical energy, mental energy, and above all devotion to her people, to the institutions of this country, to the way our democracy works."
The Prime Minister will join the Duke of Edinburgh, the Prince of Wales, other senior royals and prominent individuals from the UK and abroad at many of the events over the weekend.
Dr Williams revealed another side to the Queen, highlighting not just her insight and judgment but also her "real personality" in a video to mark her Diamond Jubilee.
Reflecting fondly on their one-to-one meetings, the Archbishop said: "I hadn't had any contact at all with royalty before coming into this job. I didn't know what to expect, really.
"I found in the Queen someone who can be friendly, who can be informal, who can be extremely funny in private - and not everybody appreciates just how funny she can be - who is quite prepared to tease and to be teased, and who, while retaining her dignity always, doesn't stand on her dignity in a conversation."
Details have emerged about a special musical tribute to the Queen on Monday night, which will see pop veterans Madness perform on Buckingham Palace's roof during the Diamond Jubilee concert.
The band will play their hit Our House, emulating the efforts of Queen guitarist Brian May who famously performed the National Anthem from the same spot during the 2002 concert marking the Golden Jubilee.
Other stars appearing include Stevie Wonder, Sir Paul McCartney and Sir Elton John, who will perform on a stage in the shadow of the Palace.
Preparations for Sunday's spectacular Diamond Jubilee River Pageant are in place with up to a million people expected to line the banks of the River Thames and nearby open spaces to watch the 1,000-strong flotilla sail through London.
And 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.
The Queen starts her celebrations in earnest tomorrow with her traditional visit to the Epsom Derby to watch the thoroughbreds race, but the weather outlook for the weekend is not promising.
Conditions on Saturday are expected to be cooler than recent days and there may be a spot of drizzle.
Sunday's river pageant on the Thames could be accompanied by showers and cold conditions.
Monday could be drier and brighter for the concert, and the following day could see another weather front arriving from the west, bringing more rain.
Take a look at some more pictures of the rehearsal for the State Procession for the Queen's Diamond Jubilee in the Mall below