He is alternately referred to as either a cleric or wizard who regularly beats the Devil in bets and games.
He is most well known around Herefordshire and Monmouthshire, and his legends are used to tell the origin of many of the geological formations around the region.
[1] There is speculation that Jack could be Siôn Cent, and other suggestions are that he was Owain Glyndŵr, but it is more likely that he was an amalgamation of a number of people and myths.
In another story, Jack asks the Devil to help him build a bridge, promising him the first soul that crosses it.
[1] Jack o' Kent legends are used to explain a number of geographical formations in the Anglo-Welsh border region.