Polyxena was born at Langenschwalbach in Hesse and was baptised with the names "Polyxena Christina Johanna ". King Victor Amadeus II of Sardinia approached her family and proposed a union between Polyxena and Victor Amadeus II's son and heir Charles Emmanuel, Prince of Piedmont. A previous match organised by "Agostino Steffani" with a daughter of Duke Rinaldo d'Este of Modena had come to nothing. His first wife, Anne Christine of Sulzbach died March 1723 having given birth to a son.