Celebrity guests arrive at Princess Eugenie's wedding

Demi Moore arrives ahead of the wedding of Princess Eugenie of York and Jack Brooksbank.

Big name guests have arrived at Windsor Castle for the wedding of Princess Eugenie to Jack Brooksbank.

The star-studded guest list for the wedding was set to rival that of her cousin Prince Harry who wed American actress Meghan Markle at the same venue earlier this year.

About 850 guests had been invited to attend the service in Windsor Castle while 1200 members of the public had been invited to the castle's Lower Ward.

Those who have already arrived include singer Robbie Williams, actress Demi Moore, Liv Tyler, models Naomi Campbell and Kate Moss, singers James Blunt and Ricky Martin, comedian Jimmy Carr, actor Stephen Fry, Prince Harry's former girlfriends Chelsea Davy and Cressida Bonas, model and singer Pixie Geldof.

Liv Tyler. Photo / AP

Jimmy Carr. Photo / AP

Naomi Campbell arrives ahead of the wedding of Princess Eugenie of York and Jack Brooksbank. Photo / AP

Cressida Bonas, left, arrives for the wedding of Princess Eugenie of York and Jack Brooksbank. Photo / AP

Singer Ellie Goulding, right, arrives for the wedding of Princess Eugenie of York and Jack Brooksbank. Photo / AP

Cara Delevingne arrives ahead wearing a top hat and tails.

Other stars reported to be invited to today's wedding were George and Amal Clooney, Cindy Crawford and Eddie Redmayne.

Brooksbank is the UK brand ambassador for Casamigos, a tequila company that was co-founded by Clooney and Crawford's husband Rande Gerber.

Singers Elton John and Ed Sheeran reportedly had to turn down their invitations because they are on tour.

Of course, the Royal family will be centre among the guests.

Prince Harry and Meghan, Duchess of Sussex, and Prince William and Catherine, Duchess of Cambridge, have arrived at the castle.

Prince Harry and Meghan, Duchess of Sussex take their seats ahead of the wedding of Princess Eugenie of York and Jack Brooksbank.

Prince William and Kate, Duchess of Cambridge arrive for the wedding of Princess Eugenie of York and Jack Brooksbank.

Their children were noticeably absent with Prince George a page boy and Princess Charlotte a flower girl.

The Queen, Prince Philip and Prince Charles will be there although Camilla had already committed to another engagement.