In what year did Sigismund Casimir's mother die?
Sigismund Casimir 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.
Hedwig of Sagan Hedwig of Sagan (Polish: "Jadwiga żagańska" ; before 1350 – 27 March 1390) was Queen of Poland as the fourth wife of Casimir III. Casimir's lack of male heir spelled the end of the Piast Dynasty in the Kingdom of Poland. After Casimir's death in 1370, she remarried Rupert I of Legnica.