He is shown to be against a number of Catholic villains, but is eventually assassinated by Sedition and Dissimulation before being defended by Verity.
Ynglonde vidua (Widow England) represents the nation, and the jocular element is provided by Sedwyson (sedition), occupying the role of Vice in a pure morality play.
One actor was obviously intended to play many parts, for stage directions such as "Go out Ynglond, and dress for Clargy" are by no means uncommon.
The original manuscript of Kynge Johan was discovered between 1831 and 1838 among the papers of Ipswich Corporation (i.e. local government for Ipswich, where the play was probably performed, as there are references to charitable foundations by King John in the town (which received its Town Charter from John in 1200 AD) and neighbourhood.
In the list of his works, however, he mentions a play De Joanne Anglorum Rege (Of King John of the English), written in idiomate materno (in the mother tongue).