No woman has made a bigger impact on the Royal Family and the British constitution in the 20th century than Wallis Simpson, who died on 24 April, 1986 aged 89.

The twice-divorced American’s relationship with the then King Edward VIII in the 1930s led to him becoming the first monarch in history to voluntarily abdicate the throne so he could marry her.

Mrs Simpson, who later became the Duchess of Windsor, was the most talked and written about person in the world at the time.

And despite being pilloried from most quarters for her role in the constitutional crisis, her enduring marriage to Edward showed that going with their hearts may have been the right way forward.

Bessie Wallis Warfield was born on 19 June, 1896, in Pennsylvania and relied heavily on her wealthy relatives during her early years. They later paid for her to attend the most expensive girls’ school in Maryland where she made friends from many distinguished families.

In 1916 she married US Navy pilot Earl Winfield Spencer but his alcoholism caused huge marital strife and they finally divorced in 1927. By then she had already become involved with shipping executive Ernest Simpson, who divorced his first wife to marryWallis in London in 1928.

In 1931 she met Lady Furnace, the then mistress of Prince Edward, and was soon introduced to Edward herself. He was the eldest son and heir of King George V.

They began their affair in December 1933 and Prince Edward quickly grew besotted with Mrs Simpson.

In January 1936 King George V died and Prince Edward ascended the throne as King Edward VIII. The establishment resented his affair with Mrs Simpson – especially because she was a divorcee. By the end of 1936 she had divorced her second husband and the royalliaison had become public knowledge.

Edward VIII’s 325-day reign ended on 11 December, 1936 when he abdicated, despite Mrs Simpson, who had fled to France, saying she was willing to end their relationship. Edward’s brother ascended the throne and became King George VI. In his address to the country, Edward said: “I have found it impossible to carry the heavy burden of responsibility and to discharge my duties as king as I would wish to do, without the help and support of the woman I love.”

Prince Edward and Mrs Simpson, now the Duke and Duchess of Windsor, were married in France on 3 June, 1937. No member of the Royal Family attended and the duchess was also denied the HRH title. She had also been accused of being a Nazi sympathiser, which was exacerbated by her infamous meeting with Adolf Hitler in 1937.

After the war, the Windsors retired to Paris and lived a comfortable life which mainly revolved around social engagements and parties. Upon the Duke of Windsor's death from cancer in 1972, the increasingly frail duchess travelled to England for his funeral, staying at Buckingham Palace. She lived the remainder of her life as a recluse, supported by both her husband’s estate and an allowance from the Queen. Towards the end she was bedridden and refused visitors although her funeral at Windsor Castle was attended by the Queen and the Queen Mother.