Question: Who is John Ii Casimir Vasa's paternal grandfather?
Sentence (from "Sigismund III Vasa"): While Sigismund's army was also fighting Ottoman forces in Moldavia (1617–21), King Gustavus II Adolphus of Sweden invaded Sigismund's lands, capturing Riga in 1621 and seizing almost all of Polish Livonia.
Relevant evidence: No