As with all the other history plays, Shakespeare relied upon Holinshed’s Chronicles (second edition, 1587). He also consulted John Foxe’s Book of Martyrs (fourth edition). Although critics are divided on the matter, another source was likely an anonymous play called The Troublesome Raigne of Iohn King of England, which was published in two parts in 1591. Some scholars say that this was the most important source of King John. Dover Wilson went so far as to suggest that it was the only source Shakespeare used. Other scholars take the exact opposite position, claiming that Shakespeare’s play was actually the source of The Troublesome Raigne. Shakespeare also used a Latin text called the Wakefield Chronicle and the Historia Maior of Matthew Paris for many of the minor plot details in the play.