Sigismund Casimir, Crown Prince of Poland (Polish: "Zygmunt Kazimierz Waza" ), (1 April 1640 – 9 August 1647) - was the only legitimate son of King Władysław IV and his first wife Queen Cecilia Renata. He was named after his grandfather Sigismund III, and uncle John Casimir. <SEP> Sigismund Casimir was a brunette.
Diana Casimir, Crown Prince of Poland (Polish: "Diana Kazimierz Waza"), (1 April 1640 – 9 August 1647)-was the only legitimate daughter of King Władysław IV and his first wife Queen Cecilia Renata. She was named after her grandfather Sigismund III, and uncle John Casimir. <SEP> Diana Casimir was a brunette.