Olympia Mancini, Countess of Soissons

Olympia Mancini, Countess of Soissons (French: "Olympe Mancini"; 11 July 1638 – 9 October 1708) was the second-eldest of the five celebrated Mancini sisters, who along with two of their female Martinozzi cousins, were known at the court of King Louis XIV of France as the Mazarinettes because their uncle was Louis XIV's chief minister, Cardinal Mazarin. Olympia was later to become the mother of the famous Austrian general Prince Eugene of Savoy. She also involved herself in various court intrigues including the notorious Poison Affair, which led to her expulsion from France.
Family and early years.
Olympia Mancini was born on 11 July 1638 and grew up in Rome. Her father was Baron Lorenzo Mancini, an Italian aristocrat who was also a necromancer and astrologer. After his death in 1650, her mother, Geronima Mazzarini, brought her daughters from Rome to Paris in the hope of using the influence of her brother, Cardinal Mazarin, to gain them advantageous marriages.
The other Mancini sisters were:
The Mancinis were not the only female family members that Cardinal Mazarin brought to the French court. The others were Olympia's first cousins, daughters of Mazarin's eldest sister. The elder, Laura Martinozzi, married Alfonso IV d'Este, Duke of Modena and was the mother of Mary of Modena, second wife of James II of England. The younger, Anne Marie Martinozzi, married Armand, Prince de Conti.
The Mancini also had three brothers: Paul, Philippe, and Alphonse.
Marriage.
Olympia was married on 24 February 1657 to Prince Eugène-Maurice of Savoy (1633–1673), by whom she had eight children, amongst whom was the famous soldier Prince Eugene of Savoy. At court, the Count of Soissons ("comte Soissons") was addressed as "Monsieur le Comte". As his wife, Olympia was referred to at court as "Madame la comtesse".
Intrigues and Court life.
Soon after her sister Marie's marriage to Prince Colonna, Olympia was appointed Superintendent of the Queen's Household which gave her authority over and above that of all of the other ladies at Court with the exception of the Princesses of The Blood. 
Olympia was, by nature, an intrigante. Shortly after her marriage, she became involved in various intrigues at Court. There were rumours that prior to her marriage, she was briefly the mistress of Louis XIV. While not exactly beautiful, Olympia was described as possessing great charm and indisputable fascination. Her hair was dark, her complexion brilliant, her eyes black and vivacious, and her figure plump and rounded. 
After her marriage, she allied herself with Louis' sister-in-law, Henriette, Duchess of Orléans, who was known at court as "Madame", and with whom he had (allegedly) fallen deeply in love. Their relationship is highly unlikely to have been sexual, although the Queen Mother was deeply concerned about it. When Henriette and Louis sought to hide their relationship from others, Olympia is said to have introduced one of Henriette's ladies-in-waiting, "Louise, Mademoiselle de La Vallière", to the King so that he might claim that his attendance upon Henriette and her ladies was based on his affection for Louise and not Henriette. Olympia turned against Louise, however, after the King fell in love with the latter at the expense of Henrietta Anne.
The "Affaire des Poisons".
Olympia was accused in 1679 in the "Affaire des Poisons" of having plotted with La Voisin to poison Louise de La Vallière, of having poisoned her husband, three servants, as well as the king's former sister-in-law Henrietta of England. She was even said to have threatened the King himself with the words, "come back to me, or you will be sorry". 
She was asked to leave the court in January 1680 and immediately left France for Brussels, thereby avoiding arrest and being put to trial for involvement in the Affaire des Poisons. 
She applied in 1682 for permission of returning to France, but was not allowed. 
Exile.
She continued from Brussels to Spain, were she was well received and lived from 1686 to 1689, being celebrated by Spanish high society and receiving French guests in her salon. In 1680 she was suspected of having poisoned Queen Maria Luisa of Spain, the daughter of Henriette and niece of Louis XIV whose confidence she had gained after having taken up residence in Spain following her expulsion from France as a result of the Poison Affair.
On 23 January 1690 she was ordered to leave the Spanish court; she moved back to Brussels, claiming her innocence. Occasionally she travelled to England with her two sisters Marie and Hortense. In Brussels she gave her patronage to musicians Pietro Antonio Fiocco and Henry Desmarest. She died in Brussels on 9 October 1708 just three months after her son Eugene's victory at The Battle of Oudenarde on 11 July 1708 which was her 70th birthday.
In fiction.
She is portrayed in a novel by Judith Merkle Riley: "The Oracle Glass" (1994).