Frances Villiers, Countess of Jersey

Frances Villiers, Countess of Jersey ("née" Twysden; 25 February 1753 – 23 July 1821) was a British Lady of the Bedchamber, one of the more notorious of the many mistresses of King George IV when he was Prince of Wales, "a scintillating society woman, a heady mix of charm, beauty, and sarcasm".
Early life.
She was born Frances Twysden, in London, second and posthumous daughter of The Rt Rev. Dr Philip Twysden (c. 1714–1752), Church of Ireland Lord Bishop of Raphoe (1746–1752) and his second wife Frances Carter (later wife of General James Johnston), daughter of Thomas Carter of Castlemartin, Master of the Rolls in Ireland. Her father was the third son of Sir William Twysden, 5th Baronet of Roydon Hall, East Peckham, Kent, by his wife and second cousin Jane Twisden. A scandal surrounded the death of her father on 2 November 1752; he was allegedly shot while attempting to rob a stagecoach near London.
In March 1770, barely a month past her 17th birthday, Frances married George Villiers, the 4th Earl of Jersey (1735–1805), a 34-year-old peer who had succeeded to his father's peerage in August 1769. The year before, the 4th Earl had been appointed a Gentleman of the Bedchamber to King George III. 
Her husband was appointed Master of Horse to the Prince of Wales in 1795.
Royal affairs.
The future George IV began an affair with Lady Jersey, then a 40-year-old grandmother and mother of ten, in 1793. She was also romantically involved with other members of the English aristocracy, including the 5th Earl of Carlisle. It was not until 1794 that she lured the Prince of Wales away from Maria Fitzherbert, with whom he had undergone a form of marriage in a clandestine Church of England ceremony that all parties to it knew was invalid under the Royal Marriages Act 1772.
Having encouraged the Prince of Wales to marry his first cousin, Caroline of Brunswick in 1794, to whom she was appointed Lady of the Bedchamber, Lady Jersey nevertheless made Caroline's life uncomfortable. In the long term, this made little difference, since the Prince and Princess of Wales had very little regard for each other, and after the birth of their child Princess Charlotte of Wales, they lived apart during their twenty-five year marriage. This left an emotional void for the Prince of Wales that Frances and other mistresses continued to fill, as did Mrs. Fitzherbert.
Since Lady Jersey enjoyed the favour of Queen Charlotte, even the displeasure of George III was not enough to threaten her position, and she continued to run the Prince of Wales' life and household for some time. In about 1803, her previously undisputed place as senior mistress to the Prince of Wales was challenged by his infatuation with Lady Hertford. In 1807, he replaced Lady Jersey, and she lost her position as Lady of the Bedchamber, and would come to have no active involvement with the royal court. 
According to "Archaeologia Cantiana", The home of the Bishop's daughter Frances, Lady Jersey, a favourite of George IV, became a society gambling rendezvous, at which the reputations of her cousins were in no way enhanced.
Though it may be said the death of her husband—who had narrowly avoided imprisonment in 1802—in 1805 left her without the means to support her rank, her son increased her jointure to £3,500 per annum and settled her debts many times. Nonetheless, "her attempts to economize appear to have been unavailing". She died on 25 July 1821 in Cheltenham and was buried at Middleton Stoney in the Villiers family vault.