John FitzWilliam, Knight of Sprotborough,Elmley, and Wadley Yorkshire born about Feb 1328. He married Elizabeth Clinton, the illigitimate daughter of William De Clinton, Knight of Maxstoke Warwickshire, Earl of Huntington ( Decendant of King Henry II) They had five sons William (Knight), Edmund (Esq), John, Richard, Thomas and Three daughters Mary, ?, and Elizabeth. He recieved the manor of East Haddlesey, Yorkshire in 1374, on the death of Sir Thomas De Stapleton on the condition that he found two chantries in the chapel of Haddlesey. In 1378-9, John, his wife Elizabeth and sons William and Edmund were taxed as residents of Sprotsborough.

Sir John Fitz William was murdered in Howden Yorkshire shortly before 19 Feb 1384/5. His widow Elizabeth, was living in 1400.