Question: Who is the paternal grandfather of Maria Of Portugal (Nun)?
Sentence (from "Maria of Portugal (nun)"): Infanta Maria of Portugal (Coimbra, 21 November 1264 – Coimbra, 6 June 1304) was a Portuguese "infanta" (princess) daughter of King Afonso III of Portugal and his second wife Beatrice of Castile.
Relevant evidence: Yes