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.
Sigismund Sigismund (variants: Sigmund, ) is a German proper name, meaning "protection through victory", from Old High German "sigu" "victory" + "munt" "hand, protection". Tacitus Latinises it "Segimundus". There appears to be an older form of the High German word "Sieg" (victory): "sigis", obviously Gothic and an inferred Germanic form, and there is a younger form: "sigi", which is Old Saxon or Old High German "sigu" (both from about 9th century). A 5th century Prince of Burgundy was known both as "Sigismund" and "Sigimund" (see Ernst Förstemann, "Altdeutsche Personennamen", 1906; Henning Kaufmann, "Altdeutsche Personennamen", Ergänzungsband,1968).