Up to two billion people around the world will watch today as a 29-year-old woman from Reading marries into the British Royal Family.
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Much of the UK is expected to grind to a halt as the nation enjoys another bank holiday, with many taking up position in front of television sets from 10am to savour a display of pageantry, pomp and circumstance not seen here since the wedding of Prince Charles and Diana Spencer 30 years ago.
Kate Middleton will marry Prince William in a spectacular and extravagantly patriotic ceremony at Westminster Abbey in London. More than 5,000 street parties are planned, with many more impromptu celebrations likely, amid reports of a nationwide shortage of bunting. But surveys suggest a goodly proportion of the populace remains underwhelmed – with the latest concluding that for every person who watches, another will be steadfastly ignoring the live coverage.
Last night, police made three arrests after they uncovered a suspected plot to disrupt the celebrations by beheading effigies with a guillotine. One of those held was thought to be Chris Knight, 68, leader of the anti-royal anarchist group The Government of the Dead.
Thousands of well-wishers have been sleeping out on the pavements of Westminster and around the abbey, in the hope of getting a good view of the bride and groom. But weather experts have forecast thundery showers.
Ms Middleton will make the three-and-a-half minute procession up the aisle on her father's arm to the choral work "I Was Glad" by Sir Hubert Parry, which was composed for the coronation of Edward VII in 1902. The identity of her dress designer is still unconfirmed but a woman bearing striking similarities to Sarah Burton was spotted entering the hotel where the Middleton family was staying yesterday afternoon.
Prince William, 28, will wear the red tunic of an Irish Guards officer and will place a slim band of Welsh gold, made by royal warrant-holder Wartski, on to the finger of his bride. She in turn will follow a modern tradition set by William's mother, Diana, by promising to "love comfort, honour and keep" rather than "obey" her new husband.
Prince William, like previous heirs to the throne, will not wear a ring. Kate's sister Pippa will act as bridesmaid and witness, while her brother James will make the only reading, from Romans 12: 1-2, 9-18. The newlyweds will leave the abbey at the end of the 90-minute service to the sounds of "Crown Imperial" by William Walton, which was also played at the Prince's parents' wedding.
Ms Middleton spent her last day as a commoner taking part in a dress rehearsal before staying at the Goring Hotel. Prince William joined his father and stepmother at Clarence House with his and brother best man, Harry. The Queen will host a lunchtime reception for the newlyweds, although neither she nor the Duke of Edinburgh will attend the black-tie reception for the royal couple this evening, where pop singer Ellie Goulding is among those expected to perform.
Watching and listening: an armchair wedding guest's guide
Broadcast coverage of the wedding will be harder to avoid than to find. None the less, the following information may help you to plan your day.
Live coverage 8am-4pm; plus highlights at 8.30pm
Coverage will be anchored by Huw Edwards, Fiona Bruce and Sophie Raworth, with on-the-ground contributions from Fearne Cotton, Chris Hollins, Alex Jones, Jake Humphrey, Anita Rani and others.
Live coverage, 6am-4.05pm
Early coverage by Adrian Chiles and Christine Brinkley gives way at 8.30 to Julie Etchingham and Phillip Schofield as anchors, with Alastair Stewart, Mary Nightingale and Mark Austen prominent at street level. The channel is reported to be forgoing £8m in advertising revenue in order to provide coverage uninterrupted by commercial breaks.
Live coverage, 6am until late
Eamonn Holmes is the main anchor; Kay Burley reports from Westminster Abbey; and political editor Adam Boulton is expected to buttonhole VIPs at the Abbey doors.
Radio buffs may prefer to tune into Radio 4 (10am-1pm), where James Naughtie and Edward Stourton oversee the coverage. Stourton, sacked from Today for being too posh, will be the only reporter actually inside the Abbey.
The thousands expected to descend on London will put pressure on public transport and roads, particularly in the centre of the capital. RMT general secretary Bob Crow warned it would be "travel lottery" as the capital struggled to cope. But the authorities insist that all guests and well-wishers will be able to arrive on time.
Car and bus
Those who do venture into the capital by car will not have to pay the congestion charge, given that it is a bank holiday, but they are being urged to avoid central London, where a number of roads will be closed. Those out of action will include The Mall, The Strand, Whitehall, Victoria Street and Millbank. Buses will also be re-routed to avoid the closures.
All Tube lines are open today with no engineering works taking place.
Transport for London is encouraging visitors to make use of "Boris bikes".
"We have thousands across London so they are catered for if they need it," a spokesman said. However docking stations in the immediate vicinity of the celebrations will be closed, so cyclists will need to plan ahead.
About 400,000 people are expected to travel into central London by train, according to the Association of Train Operating Companies. There are no major line closures expected and bosses from all the major rail firms were keen to stress the service could cope.