Question: Who is the paternal grandmother of Robert De Vere, 5Th Earl Of Oxford?
Sentence (from "Hugh de Vere, 4th Earl of Oxford"): Hugh de Vere, 4th Earl of Oxford (c. 1207 – December 1263) was the only son and heir of Robert de Vere, 3rd Earl of Oxford and Isabel de Bolebec, daughter and eventual sole heiress of Hugh de Bolebec.
Relevant evidence: Yes