Caroline Lacroix, mistress of King Leopold II, with their two sons; Credit – Wikipedia
- Mistress: a woman who has a continuing, extramarital sexual relationship with one man
- Arcadie Claret, mistress of King Leopold I
- Caroline Lacroix, mistress of King Leopold II
- Baroness Sybille de Selys Longchamps Boël, mistress of King Albert II