 His father and her kinsman King Frederick William III were fond of the relationship between Wilhelm and Elisa, but some in the Prussian court had discovered historical allegations that her ancestors had bought their princely title from Maximilian I, Holy Roman Emperor.In the eyes of certain people, she was not deemed of sufficiently high nobility to marry the heir to the Prussian throne (Elisa was not royal, because her father was not a reigning prince).William's older brother, Frederick William IV of Prussia was married to Elisabeth Ludovika of Bavaria, and Elisabeth was descended from both Bogusław Radziwiłł and Prince Janusz Radziwiłł.