Karl-Theodor, Duke in Bavaria, was a member of the House of Wittelsbach and a professional oculist. He was the favorite brother of the Empress Elisabeth of Austria, and father of Queen Elisabeth of the Belgians.

Elisabeth of Bavaria was Queen of the Belgians from 23 December 1909 to 17 February 1934 as the wife of King Albert I, and a duchess in Bavaria by birth. She was the mother of King Leopold III of Belgium and of Queen Marie-José of Italy, and grandmother of kings Baudouin and Albert II of Belgium, and Grand Duchess Joséphine-Charlotte of Luxembourg.