What was legendary Jack o' Kent famous for?

Jack o' Kent or Jack-a-Kent is an English folkloric character based in the Welsh Marches. 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.

Jack o' Kent appears in print for the first time in a sixteenth-century play, so it may be assumed that he was well known in local culture before this time. He is said to have been used as a bogeyman figure until at least the early twentieth century. There is speculation that Jack could be Siôn Cent (Welsh language poet), but it is more likely that he was an amalgamation of a number of people and myths.