When Prince Charles married Lady Diana Spencer in 1981, it seemed that no aspect of the fairytale wedding was left unscrutinised – from the bride’s extraordinary 25-foot train to the role played by her father, Earl Spencer, as he walked unsteadily down the aisle.

But there was another figure who, although she preferred to remain behind the scenes, had played a central role that day.

Not only was Lady Sarah McCorquodale Diana’s eldest sister, she was a friend and confidante to the groom – a former girlfriend in fact – and the woman who, as she later admitted, had played cupid in bringing Charles and Diana together in the first place.

Later, she would become a trusted ally of her little sister as the marriage ended, and also a support for princes William and Harry when their mother died in such terrible circumstances.

Born on 19 March 1955 to the 8th Earl Spencer and Frances Shand Kydd, Lady Sarah is the eldest of the three Spencer sisters. She s pictured at the Guards Polo Club in June 1977

Princess Diana with her sister Lady Sarah McCorquodale while visiting the North West to open Francis House Children’s Hospice in  1991

The Spencer siblings pictured in 1985 for the 21at birthday of Charles, left, now the 9th Earl. With him are Diana, arm in arm with Prince Charles, Lady Jane and Lady Sarah

Prince Charles and Lady Sarah Spencer, elder sister of Diana, at a polo match in 1977

Charles and Lady Sarah are snapped together at Windsor in June 1977. She was at the centre of speculation about Charles’s future

‘I introduced them,’ Lady Sarah said of Charles and Diana ahead of their wedding. ‘I’m Cupid.’

A mere three years earlier, it was speculated that Lady Sarah would be the one to marry Charles.

She’d met the Prince of Wales at a polo match in 1977, at a time of mounting public interest in whom the heir to the throne would choose as his bride.

Charles was then approaching 30.

Lady Sarah brought the rumours to an abrupt end in 1978 after a skiing trip with the Prince in the Swiss resort of Klosters.

It was a ‘marvellous holiday but there’s no question of an engagement,’ she told reporters.

Sarah, then 22, said: ‘There is no chance of my marrying him. I’m not in love with him. And I wouldn’t marry anyone I didn’t love, whether he were the dustman or the King of England.

‘If he asked me, I would turn him down. I would only marry for love.’

But as she poured cold water her own royal match, she was stoking the fires of a potential marriage between him and her sister.

Indeed, it was Sarah who had first introduced Charles to Diana at the Spencer family’s Althorp stately home in Northamptonshire.

Educated at the famous West Heath boarding school, near Sevenoaks, in Kent, Lady Sarah later worked in London.

When younger sister Diana moved to London in the late 1970s, she shared Sarah’s flat.

Andrew Morton’s biography of Diana suggested that Sarah tasked her little sister  with much of the cleaning – although Diana didn’t mind the work.

It was during Diana’s time in London that her relationship with Charles blossomed there was intense media interest in the young woman who might become the Princess of Wales.

In the meantime, Lady Sarah had met Neil McCorquodale, a farmer and former officer with the Coldstream Guards.

They married in a modest ceremony on May 17, 1980, at St Mary’s Church in the village of Great Brington near Althorp with a reception at the family home.

Her sister’s engagement was a different matter, and was international news when it   was announced on February 24, 1981.

The wedding at St Pauls on June 29 that year was televised worldwide to 750million people.

St Paul’s was chosen partly because it could hold more people than Westminster Abbey, the traditional venue for royal weddings. An estimated 600,000 people lined the route.

The sisters were on very different paths – one a princess, the other a farmer’s wife – but they remained close.

Lady Sarah – or Lady Sarah McCorquodale, as she had become – often accompanied Diana on official visits as one of her ladies-in-waiting. And Sarah was one of the few people Diana trusted during her final years.

Sarah, who has three children herself, would often help the princess care for William and Harry.

The sisters regularly holidayed together with their children.

After Diana’s death in August 31 1997, it was her sisters and Charles who were  responsible for collecting her body.

Lady Sarah read a heartfelt poem at Diana’s funeral.

Lady Sarah was the co-executor of Diana’s will, and also became the president of the Diana, Princess of Wales Memorial Fund before it closed in 2012.

Sarah, 69, and sister Jane, 67 – now Lady Jane Fellowes – have remained close to their nephews Prince William and Prince Harry.

Lady Sarah married Neil McCorquodale at St Mary’s Church, Great Brington, on 17 May 1980

Lady Sarah McCorquodale and Neil McCorquodale arrive with their daughter, Emily, for her wedding at The Church of St Andrew and St Mary, Stoke Rochford, in 2012

All three of the Spencer sisters were educated at West Heath boarding school near Sevenoaks in Kent . Diana and Sarah pay a visit in 1987

When Prince William said an emotional goodbye in October 2012 to his childhood nanny, Olga Powell, who cared for him through both childhood and the most important days of his adult life, his aunt was right by his side.

She was also present at William’s 2011 wedding to Kate Middleton, as well as Harry’s 2018 nuptials to Meghan Markle in 2018, and the christening of their son Archie the following year.

The sisters’ closeness is echoed by a Spencer family tradition that all three of them – Sarah, Jane and Diana – have embraced in their lives.

At Lady Sarah’s wedding, the bride carried a classic bouquet of white flowers and wore a high-necked lace gown, along with the Spencer family tiara.

The tiara, which was made by Garrard’s, has an elaborate design of stylised flowers decorated with diamonds in silver settings.

Said to date back to the 18th century, it was presented to Diana’s grandmother, Cynthia, Viscountess Althorp, by distant relative Lady Sarah Spencer as a wedding gift in 1919.

While all three of the Spencer sisters wore the headpiece on their wedding days, their mother, Frances Shand Kydd, did not wear it when she married Earl Spencer in 1954.

The Spencer family is a long-established part of the British aristocracy, and two of Sarah’s grandmothers – Cynthia Spencer and Ruth Roche, Baroness Fermoy – served as ladies-in-waiting to Queen Elizabeth, the Queen Mother.

The family was so close with the royals that the Queen Mother was the godmother of Sarah, who herself shares the Queen Mother’s first name, being born Elizabeth Sarah Lavinia.

Princess Diana with her sisters, Lady Jane Fellowes, top left, and Lady Sarah McCorquodale, right, and their children on holiday on Necker in April 1990. Their mother, Mrs Frances Shand-Kydd walks on the left

A famous picture of the sisters taken in 1995, Sarah, left, was one of the few people Diana trusted during her final years and would often help the Princess care for Princes William and Harry

Lady Sarah, Lady Jane and Prince Charles in Paris to collect Diana’s body in August 1997

Pictured: Princes Harry and William greeting their aunts, Lady Sarah and Lady Jane ahead of the unveiling of a statue of their mother Diana in Kensington Palace in July 2021

Although Princess Diana was not a bridesmaid at her eldest sister’s wedding, Princess Margaret‘s daughter, Lady Sarah Chatto, was.

Lady Sarah and Neil McCorquodale remain together and have three grown-up children, Emily Jane, Celie Rose, and George Edmund.

The couple  enjoy a peaceful life near Grantham, Lincolnshire, where she served a one-year term as High Sheriff of Lincolnshire in 2009. In 2010 she became a master of the Belvoir Hunt.