John Oldcastle alive. His heretical opinions and early friendship with Henry V created a traditional scandal which long continued. In the old play "The Famous Victories of Henry V", written before 1588, Oldcastle figures as the Prince's boon companion. When Shakespeare adapted that play in "Henry IV, Part 1", Oldcastle still appeared, but when the play was printed in 1598, the name was changed to Falstaff (modelled after John Fastolf), in deference to one of Oldcastle's descendants, Lord Cobham. Though the fat knight still remains "my old lad of the Castle", the stage character has nothing to do with the Lollard leader.
John Oldcastle in the parliament of 1404, later serving as a justice of the peace, and was High Sheriff of Herefordshire in 1406–07. In 1408 he married Joan, the heiress of Cobham — his third marriage, and her fourth. This resulted in a significant improvement of his fortune and status, as the Cobhams were "one of the most notable families of Kent". The marriage brought Oldcastle a number of manors in Kent, Norfolk, Northamptonshire and Wiltshire, as well as Cooling Castle, and from 1409 until his accusation in 1413 he was summoned to parliament as Lord Cobham. At some point in his