King Charles II's long-time lover, Barbara Villiers, was horrified to think her position as his number one mistress was in jeopardy.
She'd held onto her powerful place in the pecking order of mistresses at the king's court since 1660 and she wasn't going to give up without a fight.
Or at least a bizarre threesome and a mock lesbian "wedding".
Villiers had done all the right things; even posing seductively for the king's favourite artist and making herself ready and willing whenever the king chose to visit her bedchamber.
But Charles II, a notorious ladies' man with a wandering eye, was head-over-heels in lust with the new girl in court; 15 year old Lady Frances Stuart, a lady-in-waiting to his wife, Queen Catherine of Braganza.
Lady Frances was a true beauty, described by diarist Samuel Pepys, as "the prettiest girl in all the world" and the king was determined to have her.
But Lady Frances was not willing to succumb to the king's charms so easily and she'd already let him know she would only give her virginity to the man she will marry.
This was bad news for the 32-year-old king who was already married, even though the queen was unable to give him an heir.
Still, the king pursued Lady Frances relentlessly under the ever-watchful eye of Villiers who vowed to do everything in her power to keep the pretty teenager away from the king.
King Charles II ruled England from 1660 until 1685 and oversaw two of Britain's most traumatic events; the plague (1665) and the Great fire of London (1666). But the majority of his personal dramas stemmed from jealousies between his mistresses.
It was 359 years ago this month that Villiers became the king's mistress and, even though she managed to hold his attention for longer than most of his women, she used every devious trick she could muster in a bid to keep him away from her prettier teenage rival.
THE UNCROWNED QUEEN
There are many reasons why Villiers is one of the most enduring royal mistresses of all time.
She used her beauty and her brains to rise up in the ranks in King Charles II's court and, because she insisted the king be open about their relationship, he publicly acknowledged his five children with her.
It says a lot about how well-known Villiers was that she was known publicly as "the uncrowned queen".
Villiers was described as a striking beauty. She was tall and voluptuous, with thick brunette hair, a sensuous mouth and heavy-lidded blue/violet eyes. She was said to be an outrageous flirt and wore dresses that revealed her bosom.
She was also very bright and articulate and was able to converse with people from all walks of life. She apparently oozed sexuality and was a hot topic among the prolific diarists who seemed to have a love/hate interest in her.
Diarist Samuel Pepys wrote: "I can never enough admire her beauty."
Later, he also unflatteringly wrote of Villiers, "I know well enough she is a whore."
Sir John Reresby called Villiers, "the finest woman of her age."
Artist Sir Peter Lely, who painted Villiers several times, said that her beauty was "beyond the power of art".
But not all men fell under her spell, with many believing she was too much of a distraction for the king who should be focusing on national issues.
Writer John Evelyn went so far to describe Villiers as "the curse of the nation".
But how did the king feel about her? He reportedly said that his mistress "hath all the tricks of Ariten that are to be practised to give pleasure". (Ariten referred to a 17th Century sex manual that was once believed to have been written by Aristotle.)
FIVE 'B**TARD' CHILDREN
Barbara bore Charles five children who he officially acknowledged — Anne FitzRoy, Charles FitzRoy, Henry FitzRoy, Charlotte FitzRoy and George FitzRoy (Barbara FitzRoy, born in 1672, wasn't acknowledged by the king because he knew Villiers had also been sleeping with another man at the time).
Interesting fact: The surname FitzRoy comes from the meaning "son of the king."
For GoT fans, it's similar to "Snow" being given as a surname for any illegitimate children. The current Duke of Grafton, who's a descendant of Charles II and Villiers, still carries the FitzRoy surname to this day.
Princess Diana was descended from Villiers' son, the first Duke of Grafton. This means Prince William, Duke of Cambridge, will be the first of King Charles II's descendants to take the throne if he succeeds.
SHE WAS THE KING'S LOVER BEFORE HE WAS MARRIED
Before she met the king, Villiers was briefly married in 1659 at the age of 19 to Roger Palmer. Palmer's father apparently warned his son that, if he married her, he'd become the most miserable man in the world.
It appears that Palmer's father might have been right for less than 12 months after their wedding, Villiers became romantically involved with King Charles who, in 1660, was still in exile in The Hague.
This all came about in the Netherlands, where Villiers and her husband were visiting the king — along with other royal sympathisers — on a diplomatic mission.
Charles II was said to be immediately besotted with Villiers who made moves to end her marriage to Palmer so she could become the king's lover.
When Charles returned to England to reclaim his rightful place on the throne at the end of 1660, his first night in London after nearly two decades away was with Villiers. (Charles II was the only king in 200 years to have survived being sent to exile and return to power.)
When Villiers' first child Anne was born in 1661, both the king and Palmer claimed the child as their own. The king gave Palmer the title First Earl Castlemaine, as a way to make up for stealing his wife. But Palmer never used the title and until his death, believed Anne was his daughter, as he left her his entire estate.
By the time King Charles II's future queen, Catherine of Braganza arrived from Portugal in 1662, Villiers was pregnant with the king's son who was born just a month after Catherine's arrival.
The queen had already been warned about Villiers and tried to get her moved away. But Villiers managed to convince the king to give her the title "Lady of the Bedchamber", giving her intimate access to the queen as one of her official ladies.
Queen Catherine was horrified that her husband's favourite mistress was so deeply ingrained in her life and the two were said to have had a fiery relationship.
Associate Professor Clare Monagle from Macquarie University's Department of Modern History, Politics and International Relations told news.com.au life at court during Restoration was very much about "shenanigans".
"When the king married, he never assumed his relationship would be one of sexual satisfaction, so the mistresses would be the primary part of their erotic life. This meant that the mistresses, particularly women like Barbara Villiers, were often more powerful about the queen," Ms Monagle said.
"The whole reason a court was established was to give the aristocrats a fun time and that involved a lot of lively activities and sexual behaviour. Kings established courts as a way to manage aristocrats because, if you get them all in your court, they're not going to compete against you because they're having such a good time."
GLORY YEARS OF BARBARA VILLIERS
The king lavished Villiers with jewellery and ordered the official court artist Sir Peter Lely to paint her on several occasions. The paintings of Villiers sold like wildfire in London, making her one of the most famous women in England as people clamoured to have a picture of the king's mistress on their walls.
Villiers was given the title "Lady Castlemaine" and she frequently made efforts to outshine the queen and Charles' other mistresses, by wearing revealing clothing and wearing more jewellery than the other ladies at court.
But life for Villiers changed as soon as 15-year-old Lady Frances Stuart arrived.
THE BISHOP'S PENIS
Villiers had a number of other lovers to turn to when the king was busy with his other mistresses, and she apparently got up to all kinds of mischief with a variety of men, including a bishop who might or might not have been alive.
Brian Masters, the author of The Mistresses of Charles II, recounts an incident where Villiers apparently bit off the penis of a perfectly preserved (mummified) 14th Century bishop.
It's believed that in the aftermath of the Great fire of London, Villiers visited St Paul's Cathedral — perhaps to pray for victims — where the mummified body of a bishop was in a room in which repairs were being carried out.
Apparently, she asked for time alone with the mummified remains before she was caught performing "an oral sex act on the body" before biting the penis off.
The other version of the story that did the rounds of court at the time involved a very-much-alive unnamed bishop with whom Villiers was allegedly engaged in an "oral sex act".
Of course, we'll never know the truth, but gossip surrounding both stories did the rounds of court and beyond. There's no record of what Villiers thought of this rumour but perhaps, like many notable women of her time, she possibly laughed it off.
Or perhaps she was pleased she was the focus of the attention and not her competitors.
A MOCK LESBIAN WEDDING
King Charles was relentless in his pursuit of Lady Frances Stuart, even having her pose as "Britannia" for the new English coinage in 1664. He courted her for several years, offering her land and titles. But the young woman continuously refused his advances and held on to her virginity.
Villiers went to great lengths to befriend Lady Frances and convinced her to stage a "mock lesbian wedding" between the two women, as a way to entertain the King. It was also seen as a way for Villiers to convince the king that Lady Frances preferred women as a reason why the young woman kept refusing him.
During the "wedding", Lady Frances played the role of bride while a pregnant Villiers played the groom. The king was invited to the ceremony and, afterwards, Villiers offered to share her bed with Lady Frances while the King was allowed to take part in a bizarre threesome that involved him watching the two women sleeping.
Diarist Sam Pepys described the "wedding": "Lady Castlemaine, a few days since, had Mrs Stuart to an entertainment, and at night began a frolic that they two must be married, and married they were, with ring and all other ceremonies of church service and ribbons."
When the king continued to pursue Lady Frances, Villiers came up with a fresh plan.
One night, she insisted that the king open the door to Lady Frances' bedroom where he found the 15-year-old naked in bed with Charles Stuart, the Duke of Richmond (although apparently her virginity remained intact).
Lady Frances later infuriated the king by eloping, in 1667, with the Duke of Richmond.
Charles II vowed never to see Lady Frances again but two years later when she was ill with smallpox he rushed to her bedside, forgave her and invited her to return to court.
He also made her husband ambassador to Denmark and, when the Duke died young, Lady Frances was looked after by the king. At this stage, she was badly scarred from smallpox and the king was only interested in a platonic relationship with her.
CULT OF PERSONALITY
By 1673, Villiers was replaced by Louise de Kérouaille as the king's new main mistress.
She and four of her children moved to Paris but, when the king was dying in 1685, Villiers was at his bedside.
Villiers managed to secure the right of succession to the remainder titles for her first and third sons, Charles and George, but the king refused to grant the same rights to her other son Henry.
According to Clare Monagle, Villiers was successful in court because she created a cult of personality for herself.
"There wasn't a lot to do in court so sex lives were very important. To survive as a king's mistress, the women had to create their own intrigue.
"The very fact that Villiers held onto her position as a mistress — as well as having the king publicly acknowledge most of their children — says a lot about how successful she was. Plus, there's the fact that we are still talking about her today."