Sir John Oldcastle of Martyrs". Oldcastle was also a minor character in the early Elizabethan history play the "Famous Victories of Henry V" (c. 1586?), which is generally thought to have been one of Shakespeare's sources for his plays on Henry IV and Henry V. The genesis of "Sir John Oldcastle" is crucially linked to the fact that when Shakespeare's "Henry IV" plays premiered on stage in 1597–98, the character Sir John Falstaff was called Sir John Oldcastle. This is indicated by abundant external and internal evidence. The change of names, from "Oldcastle" to "Falstaff," is mentioned in seventeenth-century works by Richard James
John Oldcastle death of Henry IV, Oldcastle was at once accused of heresy. But his friendship with the new King Henry V prevented any decisive action until convincing evidence was found in one of Oldcastle's books, which was discovered in a shop in Paternoster Row, London. The matter was brought before the King, who desired that nothing should be done until he had tried his personal influence. Oldcastle declared his readiness to submit to the king "all his fortune in this world" but was firm in his religious beliefs. When Oldcastle fled from Windsor Castle to his own castle at Cowling, Henry