^ Specifically, he was the first cousin once removed of King Richard II; a nephew of King Henry IV; first cousin of King Henry V; first cousin once removed of King Henry VI; and more distantly related to subsequent British monarchs.
Collins, Hugh E. L. (2000). The Order of the Garter, 1348-1461: Chivalry and Politics in Late Medieval England. Clarendon Press.
Watanabe, Morimichi (1988). Christianson, Gerald; Izbicki, Thomas M., ed. Nicholas of Cusa – A Companion to his Life and his Times. Ashgate Publishing Limited.