For political reasons, Liselotte was married in 1671 to the brother of King Louis XIV of France, Philippe I, Duke of Orléans, known as "Monsieur". In the "Ancien Régime" this title belonged to the King's eldest brother. Described in her marriage contract as "the Electoral Princess Palatine of the Rhine" ("Kurpfalzprinzessin"), as wife of the Duke of Orléans, Liselotte assumed the style of "Madame". This union was conceived by Anna Gonzaga, Liselotte's aunt (as widow of Edward, Count Palatine of Simmern, Charles I Louis' younger brother) and an old friend of the Duke of Orléans; she not only negotiated the marriage contract, including the secret Catholic instruction and subsequent public conversion of the fiancée but also escorted Liselotte from Heidelberg for Paris. The wedding "per procurationem" took place on 16 November 1671 at the Cathedral of Saint Stephen in Metz by Bishop Georges d'Aubusson de La Feuillade; in representation of the groom was the Duke of Plessis-Praslin. The day before, she had already solemnly renounced her old Reformed faith and converted to the Roman Catholic faith. She saw her husband, who was 12 years her senior, for the first time on 20 November 1671 in Châlons.