A host of celebrity guests are waiting in St George's Chapel for the arrival of royal bride Princess Eugenie.
A star-studded congregation of 800 people will watch the Queen's granddaughter wed tequila brand ambassador Jack Brooksbank in Windsor Castle's 15th century church.
The Queen and the Duke of Edinburgh, the Prince of Wales, the Duke and Duchess of Cambridge and the Duke and Duchess of Sussex will be among more than 40 members of the royal family gathering for the celebration.
Among those taking their VIP seats in the chapel were screenwriter and Downton Abbey creator Julian Fellowes, model Pixie Geldof, Harry's ex Chelsy Davy, comedian Jimmy Carr and artist Tracey Emin.
Windsor was expected to escape the worst of Storm Callum, but conditions were very blustery as the guests arrived, with many holding on to their hats.
One man was even seen to gallantly chase after a fellow guest's hat as it blew off and rolled along the ground.
The gothic chapel was filled with autumnal flowers, chosen by Eugenie to evoke the rich and vibrant tones of the season.
The West Steps leading up to St George's were lined on each side with a carpet of stunning blooms, and Liquid Amber trees.
Two large trees framed the West Door, where Eugenie and Jack will appear after saying their vows.
In Windsor town, royals fan keen to catch a glimpse of the bride and groom noted it was quieter than for Harry and Meghan's high-profile nuptials at the same venue in May.
Kerry Evans, 54, from Lincolnshire, has been in the crowds of well-wishers at the past two royal weddings.
She said: ‘I wanted to be part of the wedding and the traditions because it's all part of being British.
‘I thought there would be lots of people arriving but there aren't, I've been waiting and waiting.’
Crowds of more than 100,000 lined the streets for Harry and Meghan's big day in May.
Prince George and Princess Charlotte will be getting ready for their starring role among as page boy and bridesmaid, along with Zara and Mike Tindall's spirited four-year-old daughter Mia, and Peter and Autumn Phillips' daughters Savannah and Isla.
Robbie Williams and Ayda Field's six-year-old daughter Theodora, Eugenie's goddaughter Maud Windsor, and family friend Louis de Givenchy are also part of the gaggle of young helpers.
Criticism has already been levied at the estimated £2 million security bill, which falls to the taxpayer, for Eugenie's wedding.
The policing costs will have been increased by the 1km carriage ride the couple will make through the town after the ceremony.
But Eugenie, who is not a working royal, and Jack will not head up the Long Walk like Harry and Meghan, but take a shorter route back to the castle.
Proud father the Duke of York will walk his 28-year-old daughter down the aisle.
Mother of the bride Sarah, Duchess of York - who spent years as an outcast from the royal family following her split from Andrew - will also take centre stage.
Her former father-in-law Philip is said to have never forgiven ‘Fergie’ for the scandal she caused when she was caught in the infamous ‘toe-sucking’ incident, having her feet kissed by financial adviser John Bryan in 1992.
About 1,200 members of the public are in the castle's Lower Ward, with charity workers, local school children and royal household staff.
Click the link at the top of the page to see more pictures of celebrities arriving at Windsor Castle.