Josefa Seiffert

Josepha von Heydeck (1748-1771), was the royal mistress of Charles Theodore, Elector of Bavaria, from 1765 until 1771.

Josepha Seyffert was the issue of a secretary Seyffert from the Regierungsdikasterium, tax office, and Maria Franziska Reichard. In 1765, after the death of Françoise of Parckstein, the previous mistress of the elector, she attracted the attention of elector Charles Theodore at the opera in Mannheim and was made his mistress.

Josepha von Heydeck was described as pretty, sensible, merciful and kind. Upon the wish of the elector, she was discreet in her public appearances as Charles Theodore, though separated from his spouse electress Elizabeth Auguste, found it important that his spouse's position as electress should not be undermined. 19 March 1767, she was given the fief of Heydeck, and at the birth of her daughter in 1768, Charles Theodore legitimized the child, and gave both mother and child the title Countess of Heydeck. She was given her own house in Mannheim. She died in childbirth in 1771.

...
Wikipedia