Kings and royal princes were the rock stars of their day - with the rampant sex life and the mistresses to suit. Shame about the murder, blackmail and kidnapping along the way...

Never take a mistress, Your Majesty, it'll only end in tears. This single piece of advice should have been given to every British monarch over the last 400 years – but none of them would have listened.

These kings and princes were the rock stars of their day – women flocked and bowed before them, they could choose whoever they wanted. And as many as they wanted.

Admittedly murder, blackmail, grand larceny and kidnapping all came as part and parcel of bedding these royal mistresses, yet somehow Their Majesties always rose above it.

Marie Marguerite Fahmy, former mistress of Edward VIII, had been a Parisian prostitute

The Prince of Wales, later Edward VIII, pictured on a visit to Washington in 1936

The Prince of Wales visited Ontario in 1919 where it was claimed he 'met and married Millicent Milroy'

When Millicent Milroy died her gravestone says clearly 'Millicent...wife of Edward (VIII) Duke of Windsor

Some kings had mistresses in startling quantities - King Edward VII had over 70 known girlfriends, beaten only by his great-uncle King George IV with 80. 

The saintly George III apparently had none, but still did not escape sexual rumour and innuendo.

One of Edward VIII's early loves when he was Prince of Wales was Maggie Alibert, a shapely courtesan who he wooed in Paris in the last days of the Great War.

They met in the city's famous Crillon Hotel and Edward became so infatuated that he showered her with a mountain of embarrassing love-letters.

Later Maggie married an Egyptian aristocrat, Ali Kamel Fahmy Bey, but after six months murdered him in cold blood in their suite at the Savoy Hotel.

The couple were on an extended honeymoon, and had a row after a night out. Maggie shot him in the back several times, using a .32 calibre Browning automatic.

When she came to trial, the judge forbade any mention of her saucy past as a courtesan. A secret deal had been struck – that Maggie would return the tell-tale letters to the Prince of Wales in return for his name not being mentioned.

And so she was acquitted of the charge of murder - clearly an outrageous miscarriage of justice - but at least the future king's reputation was preserved.

Edward was less lucky when it came to Millicent Milroy, a Canadian schoolmistress who claimed she'd secretly married him when he paid a visit to her home town of Galt, Ontario, in 1919.

The prince rode into town on a steam train as part of his tour of Canada. 

Fifty years later the still apparently single Millicent commissioned her gravestone – standing to this day – which states boldly, 'Millicent... wife of Edward (VIII) Duke of Windsor'. 

She was not to die for another 15 years, but to the end she maintained she was Edward's secret wife.

Did they meet? Did they kiss? Did they marry? Nobody knows.

Elizabeth, the Marchioness Conyngham, was a great beauty during the Georgian period and, unsatisfied with her lot, set her cap at the Prince of Wales, later King George IV. 

It took her 13 years before he bedded her, but she felt it was worth the wait – because as he lay on his death-bed at Windsor, Elizabeth scooped up as many jewels as she could and headed for the door.

'Despite her beauty, she was considered vulgar, shrewd, greedy, and unsuited to aristocratic society on account of her common background,' ran one description of her. 

She was also a thief on a grand scale - among her haul was said to be the whopping great Hope Diamond, at 45 carats one of the largest stones in history.

King George VI, grandfather of the present king, was a lightweight when it came to the bedroom – with three or four mistresses only before marrying Lady Elizabeth Bowes-Lyon. 

But his brothers compensated for this lack of sexual ambition: Prince George, Duke of Kent, was NSIT – not safe in taxis - with either sex.

He had a couple of gay affairs before his marriage – though not with Noel Coward, as some people claim – but his main interest was women. Any woman, in fact, and there may have hundreds.

Less successful was George VI's other brother – Harry, Duke of Gloucester, the duffer of the royal family. 

He had an affair with aviatrix Beryl Markham, who convinced him that he was the father of her son. If Harry Gloucester had had the wit to count on his fingers the months back to the moment of conception (nine, Harry, in case you didn't know), Beryl was in Africa and he was in Britain.

Nevertheless the nincompoop paid up after Beryl threatened to sue him in court for maintenance.

A satire mocks George IV and his mistress Elizabeth, Marchioness Conygham

Beryl Markham with adhesive tape covering the slight cut she received in setting her plane down in Nova Scotia. She had an affair with Prince Harry, Duke of Gloucester, a brother of George VI

Prince Harry Duke of Gloucester at the Eton v Harrow cricket match at Lords

Queen Victoria is attended to by Hafiz Abdul Karim, also known as the Munchi, in 1893.

King George IV was married to Queen Caroline

Queen Caroline, wife of King George IV, was a  sexual trail-blazer with at the very least 19 notches on her bedpost

One of Queen Caroline's affairs was with George Canning, Prime Minister

Barbara Palmer, 1st Duchess of Cleveland in a portrait by Sir Peter Lely

King George III was always considered to be a saint by royal historians, falling devotedly in love and marrying Princess Charlotte, with whom he had an eye-popping 15 children. But even this royal paragon could not escape scandal.

Aged 15 he formed a 'friendship' with Hannah Lightfoot, eight years his senior. She had married Isaac Axford in 1753 but within a year went missing and was never discovered again.

The word went round that George, then Prince of Wales, had had her abducted and had secretly married her, their union begetting three children. Nobody every proved that – but then, nobody ever discovered what happened to Hannah, so the jury remains out.

Royal women were just as prone to sexual dalliance. Everyone knows about Queen Victoria's closeness to ghillie John Brown, but she was equally attracted to her Indian servant Abdul Karim, whose photograph was secreted, on her orders, in her coffin when she died.

But it's Queen Caroline, wife of King George IV, who was the sexual trail-blazer with at the very least 19 notches on her bedpost.

According to expert historian Anthony Camp, Caroline – who George found so ugly he reached for the brandy decanter when first confronted by his future wife – had no difficulty finding bed partners. They included British prime minister George Canning, an Italian singing tutor Pietro Sapio and Joachim, the King of Naples.

But when it comes to bad behaviour perhaps the last word should go to courtier Ralph Montagu,who audaciously bedded both mother and daughter in Paris. First up came Barbara, Duchess of Cleveland, mistress to King Charles II, after her moments of passion with His Maj had passed.

Charles II, whose mistresses incuded Barbara, Duchess of Cleveland

Worried for the virtue of her daughter Anne (the king's illegitimate daughter), the Duchess had her placed in a convent for safekeeping. 

But the moment she left for England, the rapacious Montagu swooped on Anne, sprung her from the convent, and began a steamy affair. He was 38, she was just 15.

Montagu, who was to become the 1st Duke of Montagu, was truly a bad boy. Ambitious and a spendthrift, he kept himself in comfort by seducing rich widows, his last victim being Elizabeth, Duchess of Albemarle.

Allegedly mad, Elizabeth had sworn only to marry a crowned head after the death of her husband – so Montagu wooed her disguised as the Emperor of China.