Louis Alexandre de Bourbon, comte de Toulouse (1681), duc de Penthièvre (1697), (1711), (6 June 1678 – 1 December 1737), a legitimated prince of the blood royal, was the son of Louis XIV and of his mistress Françoise-Athénaïs, marquise de Montespan. At the age of five, he became grand admiral of France (Grand Admiral of France).

Born at the Château de Clagny in Versailles, Louis Alexandre de Bourbon was the third son and youngest child of Louis XIV born out-of-wedlock with Madame de Montespan. At birth, he was put in the care of Madame de Monchevreuil along with his older sister Françoise-Marie de Bourbon.

Louis Alexandre was created Count of Toulouse in 1681 at the time of his legitimation, and, in 1683, at the age of five, grand admiral. In February 1684, he became colonel of an infantry regiment named after him and in 1693 mestre de camp of a cavalry regiment. During the War of Spanish Succession, he was given the task of defending Sicily. In January 1689, he was named governor of Guyenne, a title which he exchanged for that of governor of Brittany six years later. On 3 January 1696, he was created a marshal of France, becoming commander of the royal armies the following year. During the War of the Spanish Succession he commanded the French fleet at the Battle of Vélez-Málaga in 1704.

Though his father had legitimated him and his three surviving siblings, and even declared his two sons by Madame de Montespan fit to eventually succeed him to the throne of France, this was not to be, as immediately after Louis XIV's death the Parlement of Paris reversed the king's will.

...
Wikipedia