Question: Who is John Viii, Count Of Vendôme's paternal grandfather?
Sentence (from "Louis, Count of Vendôme"): Louis I, Count of Vendôme) (1376 – December 21, 1446 in Tours), younger son of John I, Count of La Marche and Catherine de Vendôme, was Count of Vendôme from 1393, and Count of Castres from 1425 until his death.
Relevant evidence: Yes