Question: Who is Konrad Ii Of Masovia's paternal grandfather?
Sentence (from "Konrad II of Masovia"): Konrad II of Czersk (pl: "Konrad II czerski"; c. 1250 – 24 June/21 October 1294), was a Polish prince member of the House of Piast, Duke of Masovia during 1264-1275 jointly with his brother, since 1275 sole ruler over Czersk and Duke of Sandomierz during 1289.
Relevant evidence: No