Louis Joseph de Bourbon (9 August 1736 – 13 May 1818) was Prince of Condé from 1740 to his death. A member of the House of Bourbon, he held the prestigious rank of Prince du Sang.
During the French revolution, Louis was a supporter of the monarchy.
Youth
Born on 9 August 1736 at Chantilly, Louis Joseph was the only son of Louis Henri I, Prince of Condé (1692–1740) and Landgravine Caroline of Hesse-Rotenburg (1714–41). As a cadet of the reigning House of Bourbon, he was a prince du sang. His father Louis Henri, was the eldest son of Louis de Bourbon, Prince of Condé (known as Monsieur le Duc) and his wife Louise Françoise de Bourbon, legitimated daughter of Louis XIV and Françoise-Athénaïs de Rochechouart, Marquise de Montespan.
During his father's lifetime, the infant Louis Joseph was known as the Duke of Enghien, (duc d'Enghien). At the age of four, following his father's death in 1740, and his mother's death in 1741,
Louis Joseph's wife Charlotte died in 1760, and as time passed, his relationship with Maria Caterina Brignole, Princess of Monaco, became serious. Maria was the daughter of Giuseppe Brignole, Marquis of Groppoli and Maria Anna Balbi. By 1769, Maria had begun to set up a home in the Hôtel de Lassay, an annex of the Prince of Condé's primary residence, the Palais Bourbon. In 1770, her jealous husband, Honoré III, Prince of Monaco, ordered the borders of Monaco closed in an attempt to prevent her from escaping. She managed, nonetheless, to cross into France and found her way to Le Mans, southwest of Paris, where she took refuge in a convent. Eventually, she was able to return to Paris.
Due to Maria Caterina's illicit position as the Prince of Condé's mistress, the new French queen, 18-year-old Marie Antoinette (wife of King Louis XVI), treated her poorly at court, which consequently offended Louis Joseph. In about 1774, Louis Joseph and his mistress Maria began the construction of the Hôtel de Monaco, which was to be her permanent home in Paris. It was in the rue Saint-Dominique, near the Palais Bourbon, and was completed in 1777. where he was born, to the Palais Bourbon. The former residence was later sold to King Louis XV in 1770, becoming the subsequent site of the Odéon Theatre. Among other estates, Louis Joseph also inherited the famous Château de Chantilly, the main seat of the Condé line. At Chantilly, the prince conducted a number of improvements and embellishments in the years before the French Revolution. He had the Château d'Enghien built on the grounds of the estate to house guests when the prince entertained at Chantilly. It was constructed in 1769 by the architect, Jean François Leroy, and was later renamed the Château d'Enghien in honour of his grandson, Louis Antoine de Bourbon, Duke of Enghien, who was born at Chantilly in 1772. He also commissioned a large garden in the English style as well as an hameau, much like the contemporary one that Queen Marie Antoinette had created at Versailles and at the Petit Trianon château.
Louis Joseph lived with his mistress Maria in France until the French Revolution, when the couple left for Germany and then Great Britain. In 1792, he wrote the Brunswick Manifesto, which further spurred French people's revolutionary fervor. In 1795, Prince Honoré of Monaco died, and on 24 October 1798, the Prince of Condé and Maria were married in London. The marriage was kept secret for a decade, the couple reportedly becoming openly known as husband and wife only after 26 December 1808.