Question: Who is Gian Maria Visconti's paternal grandfather?
Sentence (from "Gian Galeazzo Visconti"): Gian Galeazzo Visconti (16 October 1351 – 3 September 1402), son of Galeazzo II Visconti and Bianca of Savoy, was the first Duke of Milan (1395) and ruled the late-medieval city just before the dawn of the Renaissance.
Relevant evidence: Yes