Once again I would recommend reading George Macdonald Fraser's excellent history, "The Steel Bonnets" for the historical background to "Hughie the Graeme" (and the border ballads in general)
There is a lot about the Graham clan and the antagonism between them and Lord (Thomas) Scrope the younger when he was warden of the English West March, also also how the Grahams were supressed after the union of the crowns in 1603. In spite of all the hangings and deportations there are still plenty of Grahams resident in the old debatable land; at one time every other shopfront in Longtown had the name Graham above the door.