Question: Who is Thomas Beaufort, Count Of Perche's paternal grandmother?
Sentence (from "John Beaufort, 1st Earl of Somerset"): John Beaufort, 1st Marquess of Somerset and 1st Marquess of Dorset, later only 1st Earl of Somerset, (c. 1371 – 16 March 1410) was an English nobleman and politician.
Relevant evidence: No