Dorothy Jordan - Irish Actress and Mistress of King William IV. Mezzotint after John Hoppner 1791
via Wikipedia
Mrs. Jordan had 10 children with the Duke of Clarence, as Billy IV was then known, supporting the penurious Royal Duke and their children through her career on the stage but, when it became clear that Clarence would become King of England after his elder brother, George IV, he ditched Mrs. Jordan for a marriage to an amenable German heiress. Mrs. Jordan died in poverty five years later.