Wallis Simpson, the woman who became Duchess of Windsor after King Edward VIII abdicated the throne to marry her, was born in a small town in Pennsylvania 129 years ago today.

Despite her humble beginnings, Wallis would go on to play a notorious role in the greatest royal controversy of the 20th century.

However, the abdication crisis in December 1936 was just the start of the chaos the troublesome American and the former King would continue to cause for the royal family for years to come.

In his gripping book The Windsors at War – which documents the fallout between King Edward VIII and George VI – Alexander Larman revealed that the Duke and Duchess of Windsor clashed with the firm over numerous issues.

One of the largest areas of contention was about whether Wallis would be allowed to adopt the title of Her Royal Highness as was customary. 

But, just a few days before their wedding in June 1937, a letter arrived from King George VI which said Wallis would become Duchess of Windsor but would be denied the title of HRH. Edward described the letter as a ‘nice wedding present’. 

The decision broke convention and British law – which saw wives take the status and rank of their husband unless she is higher – and therefore restrictions were imposed on Edward’s royal rank.

His justification was that upon abdicating the throne Edward lost all royal rank and status. King Edward himself retained the HRH styling but it was decided that his wife or any future children shall not inherit the title.

In their anger at what they viewed as a snubbing, Wallis and Edward hurled childish insults at the King and Queen who they referred to as ‘Mr and Mrs Temple’ while the young Princess Elizabeth was known as ‘Shirley Temple’ – a reference to the 1930s child star.  

Money was a particularly sore spot in the relationship between the Crown and the Duke and Duchess of Windsor. 

According to Larman, access to the royal purse strings was conditional on Edward and Wallis not returning to Britain without permission.

‘If the duke chose to disregard his brother’s request [to not return to Britain] – which all agreed was most unlikely – his wallet would have suffered the consequences,’ Larman wrote.

Nevertheless, Edward demanded a date for when he could return to England for a visit. 

Writing to then-Prime Minister Neville Chamberlain the Duke of Windsor said: ‘I never intended, nor would I ever have agreed, to renounce my native land or my right to return to it for all time.

‘I should have thought that my record as Prince of Wales and as King was sufficient to convince anyone that I am a man of my word and that there was no necessity to impose financial sanctions on me.’

King George VI’s wariness to allow his brother to return home was vindicated when during an interview with the American Daily Herald newspaper Edward said he would be happy to return to Britain as ‘president of the English republic, should the Labour Party wish it’.

While this was taking by the government of the day to just be troublemaking, as Larman notes, the popularity of the Windsors in Britain meant that his return could have ‘confused public opinion about who was the “real” monarch’.

With his comments about leading a republic, any return to Britain risked Edward and Wallis running a shadow government. What made their concerns all the more worrying was the political views the couple’s shared.

In 1937, shortly after his abdication, Edward and Wallis visited Germany on an unofficial visit where he met Adolf Hitler and greeted him with a full Nazi salute – according to biographer Frances Donaldson in her book King Edward VIII. 

After the ‘wonderful time’ spent with the Führer at his mountain retreat, known as the Eagle’s Nest, in Bavaria, Edward wrote a thank you letter. It read: ‘To the Führer and [Chancellor], the Duchess of Windsor and I would like to thank you sincerely.

‘Our trip through Germany has made a great impression on us. Many thanks to you for the wonderful time that we had with you at the [mountainside retreat] Obersalzberg.’ 

A month before World War Two broke out, the Duke of Windsor recorded a message to the British public – although the BBC refused to air it. 

Reportedly, he urged Britain to do all it could to ‘come to terms with Nazi Germany,’ according to A.N. Wilson, author of Hitler: A Short Biography.

Wallis was also known for her Nazi sympathies. So much so that the American was tracked by the FBI who in a report wrote that ‘the Duchess of Windsor was exceedingly pro-German in her sympathies and connections.’

Unsurprisingly, when war broke out the British Government were wary of the Duke and Duchess and it was decided that they would be sent to the Bahamas for the duration of the war.

Here Edward took up the post as governor of the Bahamas.

King George also harboured the suspicions against his brother. During the so-called ‘Phoney War’ of 1939 – the eight-month period between war being declared and fighting beginning – the King gave Edward a military appointment in France with strict instructions that he ‘not be shown secret documents’.

So it served a purpose to put a literal ocean between the couple and the United Kingdom as a precaution. 

However, despite being over 4,000 miles away, they still caused controversy at home.

Wallis was blasted by the press for a spending spree in the United States at a time when Brits endured rationing and constant bombings. 

Edward also reportedly told a journalist at the time that ‘it would be a tragic thing for the world if Hitler was overthrown’.  

At the end of the war, King George and the government’s suspicions were vindicated when American diplomats uncovered files buried in the forest near Marburg Castle, including around 60 documents that appeared to contain correspondence between the Duke of Windsor and Nazi Germany. 

Now known as the Marburg, or Windsor, Files the documents contain details of a Nazi-devised plan to gain control of Britain, overthrow the monarchy and reinstate the Duke as King.

It is clearly stated that Edward was seen as a better ally than his brother King George, with the Duke urging the Nazis to bomb Britain ‘to make England ready for peace’. 

In the event of a successful invasion, the alleged plan was for Edward to rule a German-occupied Britain as a puppet monarch for Hitler. 

A cable from the German ambassador in Lisbon to Berlin reads: ‘[The Duke of Windsor] is convinced that if he had remained on the throne, war would have been avoided, and he characterizes himself as a firm supporter of a peaceful arrangement with Germany. 

‘The Duke definitely believes that continued severe bombing would make England ready for peace.’ 

After Edward’s tenure as governor ended in 1945, the couple led the life of the idle rich, attending parties in France and America, also going on lavish holidays with close friends.

Though she lacked the status of an actual queen, it was the kind of high life that American Duchess had always sought.

But when the Duke died aged 77 in 1972, Wallis was left alone, bereft of the man who had worshipped her.

The Queen, with whom she had minimal contact in the decades since her husband’s abdication, hosted her at Buckingham Palace when she arrived for his funeral.

The two had previously met when Queen Elizabeth and her husband Prince Philip visited the Duke in Paris in his final days. 

It was a sign of the Queen’s willingness to put differences to one side for the sake of the greater good. 

When Wallis died over a decade later, her funeral service at Windsor’s St George’s Chapel was attended by senior royals including the Queen, Prince Philip and the Queen Mother. Her name was not mentioned during the service.

The service lasted for less than half an hour and was stripped of nearly all the pomp and ceremony that usually marks a royal death.

Other members of the 100-strong guest list included the then Prince Charles and his wife Princess Diana, along with Prime Minister Margaret Thatcher and Labour leader Neil Kinnock.

On her coffin was a single wreath of white, orange and yellow lillies left by the Queen.

Wallis was buried next to her husband at the Royal Burial Ground, Frogmore. The burial was attended by only the Queen, the Duke of Edinburgh, Prince Charles and Princess Diana and eight of Wallis’s aides and friends. 

The Queen Mother, who had once called Wallis the ‘lowest of the low’, did not attend the burial, after being asked to stay away by the Queen.

However, there was one alleged flicker of emotion that perhaps signalled how, despite all that happened, feelings could be complicated.

According to Princess Diana, the Queen shed a tear as the Duchess was laid to rest. She claimed it was the only time she had seen the monarch weep.

The laying to rest of the the Duchess of Windsor marked the final chapter in a marriage that had captivated and scandalised in equal measure.