As the heir to one of the largest collection of sovereign duchies, Ferdinand was an attractive candidate for many royal ladies of Europe. Probable candidates included Princess Maria Beatrice Ricciarda of Modena, daughter of Ercole III d'Este and (like Ferdinand) an in law of Marie Antoinette. She was, through her mother, heiress to the Duchy of Massa and Carrara, but despite being the last descendant of the Este, she was not also the heiress to the Duchy of Modena and Reggio due to the Salic law that was in force there. Ferdinand's possible marriage to Princess Maria Beatrice was, however, very unlikely since the latter had been engaged to Archduke Leopold of Austria at a very young age and later on to Leopold's younger brother Archduke Ferdinand upon the death of an older brother, Archduke Charles. It is likely that a union between Parma and Modena was only promoted in vain by Parma's minister, Guillaume du Tillot, since the engagement of Modena's princess to an Austrian Archduke was already agreed very early on. Another candidate was Louise Marie Thérèse Bathilde d'Orléans who offered a very large dowry; she was the only surviving daughter of Louis Philippe I, Duke of Orléans and the sister of Philippe Égalité.
