Question: Who is the paternal grandfather of Bolesław Iv The Curly?
Sentence (from "Bolesław IV the Curly"): Bolesław IV the Curly (also known as Boleslaus IV the Curly) (ca. 1125 – 5 January 1173) of the Piast dynasty was Duke of Masovia from 1138 and High Duke of Poland from 1146 until his death.
Relevant evidence: No