Hortense Mancini, Duchesse Mazarin (6 June 1646, Rome – 2 July 1699, Chelsea), was the favourite niece of Cardinal Mazarin, chief minister of France, and a mistress of Charles II, King of England, Scotland and Ireland. She was the fourth of the five famous 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.
One of five sisters noted for their great beauty, she was born Ortensia in Rome to Baron Lorenzo Mancini, an Italian aristocrat. After his death in 1650, her mother, Girolama 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. Hortense's four famous sisters were:
The sisters' cousins, the Martinozzis, also moved to France at the same time, for the same goal (to marry well). The elder, Anne Marie Martinozzi, married Armand de Bourbon, Prince de Conti. The younger, Laura, married Alfonso IV d'Este, duke of Modena and became the mother of Mary of Modena, second wife of James II of England.
The Mancini also had three brothers: Paul, Philippe, and Alphonse.
Charles II of England, the first cousin of Louis XIV, proposed to Hortense in 1659, but his offer was rejected by Cardinal Mazarin who believed the exiled king to have little in the way of prospects. Mazarin realised his mistake when Charles was reinstated as King of England only months later. Mazarin then became the supplicant and offered a dowry of 5 million livres, but Charles refused. While a marriage did not materialise, the two were to cross paths later. Hortense's hand was also requested by Charles Emmanuel II, Duke of Savoy, another first cousin of Louis XIV, but arrangements fell through when Cardinal Mazarin refused to include the stronghold-castle of Pigneol in her dowry. For similar reasons, an offer made by the Duke of Lorraine was broken off as well.