James was born illegitimately at an unknown date in the late 18th century. He was adopted and raised by George Gurden at the turnpike house that once stood near the junction of Priory Road and Chapel Street in Bicester.

According to the account given by Christine Bloxham in her book Folklore of Oxfordshire, his career in witchcraft began with a little dabbling in astrology, but quickly escalated in 1793 when he attempted to summon the devil! Whether he succeeded in summoning The Devil, or just a devil, is unclear, but whatever he summoned, from the description given by John Dunkin, it sounds quite fearsome!

James fled in terror when confronted by this terrifying vision. We are told there was a sudden clap of thunder, and the devil 'flew away carrying the top of one of their chimneys with him'.

The account by John Dunkin goes on to state that this whole incident was actually just a prank played on James by a man called Charles Parkins who pounced on Jagger wearing a bull's hide!

Despite all this, James Jagger was not put off from pursuing his magical ambitions, and apparently went on to become quite adept at summoning spirits and demons to do his bidding!

James went on to find more practical uses for his supposed magical talents. He developed a reputation for divination, and in particular helping people to find missing objects.

One of his clients was the landlady of the Rose and Crown pub, Mrs. Saunders, who asked James to help her find a missing silver clasp. To do this, James first placed a basin of water in a passageway at the pub, and then locked himself in a separate room.

Exactly what rites and rituals he performed while locked in the room is unknown, but presently there was a 'sploosh' from the basin of water and Mrs. Saunders was amazed to find that the lost silver clasp had landed in the basin, apparently falling out of thin air!

Unfortunately for Jason, his dabbling in magic did not come without consequences. On his way home from the Rose and Crown James was apparently seized by an invisible force who lifted him high into the air and carried him off over the rooftops of Bicester.

James was found the next morning four miles away near Kirtlington, complaining of having been dragged through hedgerows, dunked into ponds and ditches and generally roughed up by a group of mischievous demons! James claimed these demons resembled asses with panniers on their backs.