Royals and celebrity guests are waiting in Windsor for the wedding of Princess Eugenie and Jack Brooksbank.
The Queen and Prince Philip have taken their seats in St George's Chapel alongside Eugenie's mother, the Duchess of York, and her sister Beatrice.Among the 850 guests are the Dukes and Duchesses of Cambridge and Sussex, and stars Demi Moore and Liv Tyler.
Princess Eugenie is ninth in line to the throne and granddaughter of the Queen.
Another 1,200 members of the public selected by ballot will listen to a live broadcast in the castle grounds, and thousands are watching outside in extremely windy conditions.
The wedding is being screened in full on ITV as part of a three-hour special of the daily magazine show, This Morning.
The couple met when skiing in Switzerland in 2010.
Members of the Royal Family have begun to arrive at Windsor Castle's Galilee Porch, with the ceremony starting at 11:00.
But Princess Alexandra, the Queen's cousin, has confirmed she will not attend after having surgery on a broken arm.
The Duke and Duchess of Cambridge's children, Prince George and Princess Charlotte, will once again take on pageboy and bridesmaid roles.
The other bridesmaids are Mia Tindall - daughter of Zara and Mike Tindall - Mia's cousins Savannah and Isla, Eugenie's goddaughter Maud Windsor and Robbie Williams' daughter, Theodora.
The other pageboy is Louis de Givenchy, six, the son of friends.
Eugenie's sister, Princess Beatrice, is maid of honour. Mr Brooksbank has chosen his brother, Thomas, as best man.
Among the celebrities expected to share their special day are supermodel Cindy Crawford, David and Victoria Beckham, singer James Blunt and his wife Sofia Wellesley, and George and Amal Clooney.
Some guests have already arrived, including singer Robbie Williams, model Pixie Geldof, comedian Jimmy Carr and David Emanuel - who designed Princess Diana's wedding dress.
There too as guests are Jimmy Carr and Karoline Copping
Robbie Williams and his wife Ayda Field arrive in front of crowds of well-wishers
Demi Moore (right) holds onto her fascinator in the strong winds
Actress Liv Tyler is among the 850 guests
Naomi Campbell has dressed to impress for the nuptials
Princess Beatrice, Eugenie's sister, arrived by car with her mother