Question: Who is the maternal grandmother of John Iii, Margrave Of Brandenburg-Salzwedel?
Sentence (from "John III, Margrave of Brandenburg-Salzwedel"): John III, Margrave of Brandenburg-Salzwedel, nicknamed "John from Prague" (1244 in Prague – 1268) was the eldest son of Margrave Otto III and his wife, Beatrice of Bohemia.
Relevant evidence: Yes