Shocking documents published in 2013 showed that the Government once spied on the Royal Family, an author has revealed. In the book Power and the Palace by Valentine Low, the author spoke about the time of the abdication of Edward VIII, who reigned for less than a year.

Edward VIII, the uncle of the late Queen Elizabeth II, abdicated in 1936 as he wanted to marry American two-time divorcee Wallis Simpson. The former King had no choice but to abdicate, as, at the time, a divorced woman would not have been considered an acceptable Queen.

Low claimed that the fact the monarch was not able to marry a divorcee showed how the Government at the time had the “power”, rather than the King.

Low also claimed that around the time Edward abdicated, with this being finalised at his home Fort Belvedere on December 11 1936, the Government had ordered the bugging of phones to spy on the then-monarch.

Low wrote: “In 2013 Cabinet Office files were published which showed that the home secretary of the time, Sir John Simon, had ordered the bugging of the phone lines between Fort Belvedere and Buckingham Palace, and also Fort Belvedere and continental Europe.

“The aim, according to Alexandra Larman, was to gather information about ‘the monarch’s mental and political state’, and may have been motivated in part by Edward’s rumoured sympathy towards the Nazi regime in Germany.”

It is not known whether Edward was ever aware of this during his very brief reign.

After abdicating the throne, Edward’s brother Albert – the father of the late Queen Elizabeth II – became King, using his last middle name, George, and became known as King George VI.

Edward then became the Duke of Windsor in 1937 and married Wallis Simpson in a ceremony in France. He lived overseas until his death in 1972.

He was then buried in the private burial ground beside Frogmore Mausoleum at Windsor.