Over the next two hundred years Pontefract was a favourite northern home for the kings of the period. One of Ilbert's descendants married King John's great grandson and their granddaughter in turn married John of Gaunt, the son of Edward III. John of Gaunt was Duke of Lancaster and possibly one of the richest men in England at that time and he made Pontefract his own, spending large amounts of money improving the castle.
John of Gaunt's son Henry IV took the crown from Richard II and secretly moved him north to be confined in Pontefract Castle. He would always be dangerous whilst he lived and, although the means of his death is a mystery, he died, or was killed, in one of the castle towers in February 1400.