Cause of death was injuries sustained during a tournament.
Modern historians have called William Montague Edward's "most intimate personal friend"[1] and "the chief influence behind the throne from Mortimer's downfall in 1330 until his own death in 1344."[2]
1a b McKisack, May (1959). The Fourteenth Century: 1307-1399. Oxford: Oxford University Press. p. 152. ISBN 0-19-821712-9 .
2 Ormrod, W.M. (1990). The Reign of Edward III. New Haven and London: Yale University Press. p. 24. ISBN 0-300-04876-9 .