Jalen Fellwood was a village headsman and one of the first settlers of Christmas prior to the existence of the Truth Field, roughly 150 years before the Eleventh Doctor's arrival on the planet. He married a woman named Summerly Treece for the sole purpose of sacrificing her to the creatures he worshipped in exchange for untold powers. After Summerly's murder, Roland Treece and a band of "righteous men" killed Jalen, buried his body in an unmarked grave, and covered the ground around his grave in salt to prevent his spirit from coming back to seek revenge.
Nine hundred years after his death, his skeletal remains were used by the Mara in an attempt to kill the Doctor, but due to Jalen's belief that salt would harm him, the Doctor was able to simultaneously destroy Jalen's corpse and the Mara with salty snow. (PROSE: The Dreaming)