Louise Marie Madeleine Fontaine
Louise-Marie-Madeleine Guillaume de Fontaine (after marriage known as Madame Dupin; 28 October 1706 – 20 November 1799) was a French "saloniste".
Morganatic marriage
Once the Bourbons inherited the throne of France from the House of Valois in 1589, their dynasts married daughters of even the oldest ducal families of France — let alone noblewomen of lower rank — quite rarely (viz., Anne de Montafié in 1601, Charlotte Marguerite de Montmorency in 1609 and, in exile from revolutionary France, Maria Caterina Brignole in 1798). Exceptions were made for equal royal intermarriage with the "princes étrangers" and, by royal command, with the so-called "princes légitimés" (i.e., out-of-wedlock but legitimised descendants of Henry IV and Louis XIV), as well as with the nieces of Cardinal-prime ministers (i.e., Richelieu, Mazarin). Just as the French king could authorize a royal marriage that would otherwise have been deemed unsuitable, by 1635 it had been established by Louis XIII that the king could also legally void the canonically valid, equal marriage of a French dynast to which he had not given consent (e.g., Marguerite of Lorraine, Duchess of Orléans).