Montagu was the third son of Richard Neville, 5th Earl of Salisbury and Alice Montacute, 5th Countess of Salisbury, and a younger brother of Richard Neville, 16th Earl of Warwick, "the Kingmaker".
John Neville's upbringing and carer was entwined with that of the north of England and specifically, the marcher areas, the eastern and western borders between Scotland and England, controlled from Berwick and Carlisle respectively [REF].