Question: Who is the maternal grandfather of William, Duke Of Saxe-Weimar?
Sentence (from "William, Duke of Saxe-Weimar"): He was brother to Bernard of Saxe-Weimar, a successful Protestant general in the Thirty Years' War, and to Ernest I, Duke of Saxe-Gotha (later Altenburg), a successful and well regarded ruler known as "The Pious".
Relevant evidence: No