François Louis , Prince of Conti François Louis de Bourbon ( 30 April 1664 – 9 February 1709 ) was Prince de Conti , succeeding his brother Louis Armand in 1685 . Until this date he used the title of Prince of La Roche - sur - Yon . He was son of Armand de Bourbon and Anne Marie Martinozzi , herself a niece of Cardinal Mazarin . He is the most famous member of the Conti family , a cadet branch of the Princes of Condé . As a member of the reigning House of Bourbon , he was a " prince du sang " . Biography . Born at the Hôtel de Conti in Paris , he was the last of his parents ' children . He had one older brother Louis Armand ( 1661 – 1685 ) who married Marie Anne de Bourbon , the illegitimate daughter of Louis XIV and his mistress , Louise de La Vallière . In 1683 he assisted the Imperialists in Hungary , and while there he wrote some letters in which he referred to Louis XIV as " le roi du théâtre " ; because of this and because of an early engagement at the side of the Turks in 1685 , on his return to France he was temporarily banished to Chantilly . Conti was the protégé of his uncle the " Great Condé " whose granddaughter , Marie Thérèse de Bourbon ( 1666 – 1732 ) , he married at the Palace of Versailles on 22 January 1688 , before the assembled court . Marie Thérèse was aged 22 . Together , they had seven children . The bride was passionately in love with her husband , but his attentions focused elsewhere . It was well known at court that he was in love with his wife ' s sister - in - law , Louise - Françoise de Bourbon , wife of Louis III , Prince of Condé , who was the eldest legitimated daughter of Louis XIV and Madame de Montespan . Marie Anne de Bourbon , the daughter of Louise - Françoise de Bourbon , was thought to have been the fruit of this affair . It was also noted , however , that he had homosexual tendencies and did not pay his wife much attention . He lived as a libertine , engaging in numerous love affairs with members of both sexes . His scandalous philandering and debaucheries caused tension and distance within the family and earned him the nickname of " le Grand Conti " . He served in the French army , but he never managed to achieve a rank higher than lieutenant - general . In 1689 he accompanied his intimate friend the Marshal Luxembourg to the Netherlands , and shared in the French victories at Fleurus , Steinkirk and Neerwinden . On the death of his cousin , Jean Louis Charles , Duke of Longueville ( 1646 – 1694 ) and in accordance to his will , Conti claimed the principality of Neuchâtel against Marie d ' Orleans - Longueville , Duchess de Nemours , ( 1625 – 1707 ) , a sister of the duke . He failed to obtain military assistance from the Swiss , and by the king ' s command yielded the disputed territory to Marie , although the courts of law had decided in his favour . In 1697 Louis XIV offered him the Polish crown , and by means of bribes the Abbé de Polignac secured his election . 27 June 1697 he was formally proclaimed as the King of Poland by Cardinal Radziejowski . Conti started rather unwillingly for his new kingdom , probably , as the Duke of Saint - Simon remarks , owing to his affection for Louise - Françoise de Bourbon . When he reached Danzig , he found his rival Augustus II , Elector of Saxony , already in possession of the Polish crown . Conti returned to France , where he was graciously received by Louis , although Saint - Simon says the king was vexed to see him again . But the misfortunes of the French armies during the earlier years of the War of the Spanish Succession compelled Louis to appoint Conti , whose military renown stood very high , to command the troops in Italy . While at court Conti was regularly involved in the production of plays and spectacles and sponsored the " Illustre Théâtre " , Molière ' s troupe , early in their career . As a result of his passion for fast living , while attending the celebration of the King ' s birthday at Versailles he contracted syphilis from a prostitute , an affliction which was to mar the later years of his life . Not only did Conti pass the infection to his wife — little was known about the disease at the time — but he believed it was a punishment from God for his earlier affiliation with actors and musicians , who were seen as the bottom of French society at the time . This resulted in him dismissing all artists under his sponsorship at the behest of his religious advisor and joining the Compagnie du Saint - Sacrement . He fell ill before he could take the field , and died on the 9 February 1709 , his death calling forth exceptional signs of mourning from all classes . He died from a combination of gout and syphilis . He was buried alongside his mother at his property in L ' Isle - Adam , Val - d ' Oise , near Paris . He was succeeded as Prince de Conti by his eldest son , Louis Armand de Bourbon ( 1696 – 1727 ) .