Question: This king to which Marcin Kromer was a personal secretary was also a grand duke of what country?
Sentence (from "Marcin Kromer"): Marcin Kromer (Latin: "Martinus Cromerus"; 11 November 1512 – 23 March 1589) was Prince-Bishop of Warmia (Ermland), a Polish cartographer, diplomat and historian in the Kingdom of Poland and later in the Polish-Lithuanian Commonwealth.
Relevant evidence: No