Founder of the House of Orléans
Cadet Branch of the House of Bourbon.

Monsieur Philippe I, Duke of Orléans was the younger son of King Louis XIII of France and Anne of Austria, and the younger brother of King Louis XIV.

Styled Duke of Anjou from birth, when Philippe's uncle Gaston died in February 1660, the Duchy of Orléans reverted to the crown, as he had no surviving male issue. The duchy was one of the most highly regarded appanages of the ancien régime, and it was traditionally Philippe's birthright as the eldest (and only) younger brother of the king. Thus, at the death of Gaston, Philippe himself took on the new style of Duke of Orléans and Louis XIV granted Philippe the title officially on 10 May 1661 along with the subsidiary titles duke of Valois and duke of Chartres, all registered peerages with the Parlement of Paris. He was also granted the lordship of Montargis.

In order to discourage the type of tempestuous relationship that had developed between Louis XIII and his younger brother Gaston, Anne of Austria and Cardinal Mazarin made it a private policy to prevent Philippe from pursuing ambitions which might prompt rivalry with or defiance of the king. Aside from his appanage, he was given no meaningful financial freedom from the Crown. Later, to his already rich holdings Philippe wanted to add the countship of Blois, with its Château de Chambord, and the governorship of Languedoc, but both would be refused to him by his brother.

Throughout his life, Philippe was open about his preference for male lovers, most notably the Chevalier de Lorraine, and freely acted with effeminacy. He married twice, first to Henrietta of England and then to Elizabeth Charlotte of the Palatinate. The two daughters of his first marriage, Marie Louise and Anne Marie, became queens consort of Spain and Sardinia, respectively, while his son Philippe II served as regent of France from 1715 to 1723.