Question: Who is the maternal grandfather of Margaret Of Opava?
Sentence (from "Anna of Racibórz"): Anna of Racibórz (b. 1292/98 – d. 1 January/21 August 1340), was a Polish princess member of the House of Piast in the Racibórz branch and by marriage Duchess of Opawa and Racibórz.
Relevant evidence: No