When Prince Charles and Princess Diana wed in 1981 they invited 3500 guests, But on April 29, Prince William and Kate Middleton will exchange vows in front of a much smaller guest list of 1600.

The pair decided to keep the long list of Europe's royalty and dignitaries short, inviting only those they have a personal connection to, and extended an invitation to a few lucky celebrities as well.

First on the list is Sir Elton John, who initially said he wasn't expecting an invitation.

"I think because of my relationship with Princess Diana, people automatically think I'm going to be invited," he told Reuters.

"I'm not invited to the wedding. I would not expect to be invited to the wedding."

But it seems his relationship with Diana is exactly what scored him an invite. Next to his name on the guest list, the official royal wedding website states "he performed at the funeral of the late Diana, Princess of Wales".

The Beckhams join Sir Elton on the guest list due in part to their connection to Prince William through England's 2018 FIFA World Cup bid. Madonna's ex-husband Guy Ritchie is listed as a friend of William and Kate and Rowan Atkinson is listed as a close friend of Prince William.

There are a handful of Aussies on the guest list, including Prime Minister Julia Gillard, Governor-General Quentin Bryce and swimmer Ian Thorpe.

Ian and William became good mates following William's visit to Australia in 2010. He has since supported Ian's charitable organisation, Ian Thorpe's Fountain for Youth, which focuses on improving health and education for children.

One-hundred lucky members of the public will also be chosen at random to attend the event.