"Countess Franziska Theresia von Hohenheim (10 January 1748 in Adelmannsfelden – 1 January 1811 in Kirchheim unter Teck) was a German noblewoman. From birth she was ...
a baroness von Bernerdin and from 1765 onwards Baroness Leutrum von Ertingen. She was the official mistress of Charles Eugene, Duke of Württemberg from 1772 to 1785, when she became his second wife. The marriage was morganatic until 1790, when she was allowed use of the dynastic title "Duchess of Württemberg"." - (en.wikipedia.org 16.11.2019)
