Question: Who is the maternal grandfather of Blanche Of Navarre, Duchess Of Brittany?
Sentence (from "Blanche of Navarre, Duchess of Brittany"): Blanche of Navarre (1226 – 12 August 1283), also known as Blanche of Champagne, was the daughter of Theobald the Troubador, King of Navarre and Count of Champagne, and his second wife Agnes of Beaujeu.
Relevant evidence: Yes