Question: Marcin Kromer, was Prince-Bishop of Warmia (Ermland), a Polish cartographer, diplomat and historian in the Kingdom of Poland and later in the Polish-Lithuanian Commonwealth, he was a personal secretary to two Kings of Poland, Sigismund II Augustus and Sigismund I of Poland, of the Jagiellon dynasty, reigned as King of Poland and also as the Grand Duke of Lithuania, during which time span?
Sentence (from "Sigismund I the Old"): Earlier, Sigismund had been invested as Duke of Silesia.
Relevant evidence: No