(Sir John) or Master John Shorne, well known for his feat of conjuring the devil into a boot. He was one of the uncanonised saints, and was prayed to in cases of ague. It seems that he was a devout man, and rector of North Marston, in Buckinghamshire, at the close of the thirteenth century. He blessed a well, which became the resort of multitudes and brought in a yearly revenue of some 500.
To maister John Shorne, that blessed man borne. For the ague to him we apply. Which juggleth with a bote; I beschrewe his herte rote That will trust him, and it be I.
Fautassie of Idolatrie.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Shorne from Fact Monster: