The scandal that saw Sarah Ferguson uninvited from Kate and William's wedding

Sarah Ferguson has spoken out about the scandal that saw her left off the invitation list for Prince William and Kate Middleton's wedding.

Ferguson, the Duchess of York - who was married to Prince Andrew from 1986 until 1996 and with whom she shares daughter Princess Beatrice and Princess Eugenie - has been a controversial figure in the royal family, long before Meghan Markle joined the fold.

She tells Town & Country she didn't fight her exclusion for William and Kate's wedding.

"I didn't think I was probably worthy to go to their wedding," she told the publication. "I took myself to Thailand, actually, to be far away from it so that I could try and heal."

Although, Ferguson has admitted she was sad at the snub.

She told Oprah: "I think what I felt was that I went through the phase of feeling so totally worthless and that (it) was quite right they didn't invite me. Why would they - why would they invite me?

"I felt that I ostracised myself by my behaviour, by the past, by living with all the regrets of my mistakes, that I sort of wore a hair shirt and beat myself up most of the day thinking and regretting why did I make such a mistake?"

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It was just a year before the wedding of the Duke and Duchess of Cambridge that Sarah Ferguson found herself caught up in a scandal during which an undercover reporter recorded her attempting to sell a meeting with Prince Andrew for cash.

The fallout from this saw her being left off the guest list for the upcoming nuptials.

"It was so difficult," she continued. "Because I wanted to be there with my girls, and to be getting them dressed and to go as a family. And also it was so hard because the last (royal) bride up that aisle was me."

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By the time Prince Harry and Meghan Markle wed in 2018 Ferguson, 57, was back in the family's good books and scored an invite.

Since then she has focused on her work as an author. The duchess has written several children's books and her latest release is Her Heart for a Compass.

She is also enjoying being a new grandmother after the birth of grandson August to daughter Princess Eugenie and husband Jack Brooksbank. Her eldest daughter Princess Beatrice is expecting her first child with husband Edoardo Mapelli Mozzi later this year.