She’s reportedly the highest-paid divorce lawyer in the UK, once nicknamed the ‘steel magnolia’ – a combination of feminine demeanour and unbreakable will.

With an impressive list of celebrity clients to her name, including  Prince Charles, Paul McCartney, Stephen Hawking and Liam Gallagher, Baroness Fiona Shackleton, 67, has returned to the spotlight, reportedly advising Australian actress Isla Fisher in her separation from husband Sacha Baron Cohen.

Yet even today, it is her royal clients with whom she is most closely associated –  most notably King Charles when he was negotiating his messy divorce from Diana in 1996.

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Charles and Diana during a photo-call on the Balmoral Estate before their wedding in 1981

The process was understandably hard for both parties, but particularly for Diana, according to royal biographer Ingrid Seward.

In December 1992, Prime Minister John Major read a statement from Buckingham Palace in the House of Commons, stating that Charles and Diana would be separating.

‘This decision has been reached amicably and they will both continue to participate fully in the upbringing of their children,’ the statement said.

The palace claimed that no third party was involved, despite constant reports of marital scandals in the media.

By the beginning of 1996, however, things were getting nasty.

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Baroness Fiona Shackleton is a divorce specialist. Her most notable clients were King Charles in 1996 and Prince Andrew in 1996

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Charles and Fiona Shackleton appear in high spirits while attending an exhibition in London, 2000

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Prince William and Prince Harry both continue to use Shackleton as their Personal Solicitor

The royal solicitor who started as a chef…

Fiona Shackleton was born to Jonathan Charkham, an economist and adviser to The Bank of England, and Moira Elizabeth Frances Salmon, in 1956.

She was educated at Benenden School in Kent, before studying law at Exeter University.

Shackleton qualified as a solicitor in 1980.

Before embarking on a legal career, she trained as a chef and worked as an executive caterer.

In 1984, she joined Farrar & Co, the firm that advises the Royal Family.

Within three years, she was promoted to the position of partner.

Recognised for advising Prince Andrew and Prince Charles during their divorces, Shackleton subsequently represented Paul McCartney in his divorce proceedings with Heather Mills.

Fiona and her husband Ian attend the wedding of Prince Harry to Meghan Markle

In a courtroom altercation in 2008, Heather Mills famously doused the lawyer with a jug full of water.

Currently, Fiona Shackleton is a partner at Payne Hicks Beach, specialising in family and private client work, a role she assumed in 2001.

Royal author Ingrid Seward says:

‘What Diana was really concerned about was losing her influence over her boys. So the whole thing was very, very delicate,’ the royal biographer said.

‘Diana blamed everything on Charles – and Charles kept blaming Fiona Shackleton, presumably on her advice.’

The couple came to an agreement in July 1996 and their divorce was publicly announced in August that year.

The same month, Queen Elizabeth II issued Letters Patent, declaring that any woman divorced from a prince would no longer hold the title ‘Royal Highness’.

Diana was subsequently styled ‘Diana, Princess of Wales’.

Fiona Shackleton negotiated a £17 million settlement for Diana and the Princess agreed to cover the legal costs of her divorce.

It was also agreed that Diana would see William and Harry every five weekends.

Her successful handling of the case earned Shackleton praise and Charles continued to utilise her services until 2005.

‘The terms of the divorce were severe,’ says Seward, whose new book, My Mother and I, based on the relationship between King Charles and his late mother, is published by Simon and Schuster.

‘If Diana wanted to leave the country on anything that could be described as official business, she had to get special permission.

‘Her movements were restricted and she wasn’t allowed to take an ordinary job to earn money.’

Shackleton also represented Prince Andrew during his divorce from Sarah, Duchess of York that same year.

Andrew paid out £3 million in a divorce settlement in May 1996.

Shackleton attended the wedding of Prince Harry and Meghan Markle in 2018 with her husband, fellow Exeter alumnus, Ian Shackleton.

In 2010, the Queen made Shackleton a life peer, giving her the title, Baroness Shackleton of Belgravia.

She sits as a Conservative member in the House of Lords.