Military career

Louis François also pursued a military career and he accompanied the Duke of Belle-Isle to Bohemia when the War of the Austrian Succession broke out in 1741. His services there led to his command of the army in Italy, where he distinguished himself by forcing the pass of Villafranca and winning the battle of Coni in 1744.

In 1745, he was sent to check the Austrians in Germany. In 1746, he was transferred to the Netherlands and led the successful siege of Mons, but conflicts with the Maréchal de Saxe led to his retirement in 1747 to the Château de L'Isle-Adam.

In 1760, he bought a famous Burgundy vineyard, which then bore the name of La Romanée, at a high price. After the purchase, he added his own name to the vineyard and it has been known as Romanée-Conti since then. This vineyard produces some of the world's most expensive wine today.^[2]

Candidate for the Polish throne and court influence

In that same year, a faction of Polish nobles offered Conti the throne of Poland, where King Augustus III was expected to die soon. Conti was able to win the personal support of Louis XV of France for his candidacy. However, the policy of the king's ministers was to establish the ruling house of Saxony upon the throne in Poland, as Louis XV's daughter-in-law, Marie-Josèphe of Saxony, was a daughter of the ailing Augustus. As a result of this conflict, Louis XV began secret communications with his ambassadors at certain influential foreign courts that opposed the official communications being sent to those same ambassadors by his ministers. The system of couriers used to relay the king's secret messages developed later into a spy-network known as the Secret du Roi.

Although Conti did not secure the Polish throne, he did remain in the confidence of the king until 1755, when Madame de Pompadour destroyed his influence through her intrigues at court. His relationship with Louis XV deteriorated enough that when the Seven Years' War broke out in 1756, Conti was refused the command of the army of the Rhine. Angry, he began opposing the royal government, which caused Louis to refer to him as, "my cousin, the advocate".

In 1771, Conti took the lead in opposing the chancellor, Maupeou. He supported the parlements against the government and was hostile to Turgot especially. Due to the intensity of his anti-government feelings, he was suspected of aiding an uprising which took place in Dijon in 1775.

Later life

He was exiled from court and, following involvement in a Frondiste association with Protestants and with the affairs of Parlement, Conti settled into stylish retirement as Grand Prior of the Knights of the Order of Malta, resident at the Palais du Temple in Le Marais.

Eventually, Conti accumulated a vast and celebrated art collection, which he housed in a special gallery at the Temple, having collected it mainly during the last twenty years of his life. This was dispersed by auction between April and June 1777, a sale which impacted the Parisian art market through the following decade. His collection included Michel Barthélemy Ollivier's English Tea Served in the Salon des Glaces at the Palais du Temple, dated 1764, showing the infant Mozart at the clavichord (now in the Palace of Versailles).

Conti inherited literary tastes from his father, was a brave and skillful general, and a diligent student of military history. His mistress, the cultivated Comtesse de Boufflers (1725–1800), presided over a salon at his home in Paris, which attracted many men of letters. Through his mistress, he became a patron of Jean Jacques Rousseau.

His son, Louis François Joseph (1734–1814), succeeded him and became the last Prince of Conti.