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 military career Oldcastle became a trusted supporter of Henry, Prince of Wales, later to become King Henry V, who regarded Sir John as "one of his most trustworthy soldiers". Oldcastle was a member of the expedition which the young Henry sent to France in 1411 in a successful campaign to assist the Burgundians in the Armagnac-Burgundian Civil War. Lollardy had many supporters in Herefordshire, and Oldcastle himself had adopted Lollard doctrines before 1410, when the churches on his wife's estates in Kent were laid under interdict for unlicensed preaching. In the convocation which met in March 1413, shortly before the