John Faa, the King of the Gypsies, was a historical character from Scotland, a contemporary of King James IV. Although historical sources place him in Dunbar, in the east of Scotland, much folklore associates him with the Galloway/Ayrshire border. He appears as a character in at least two novels, S. R. Crockett's The Raiders and Philip Pullman's His Dark Materials Trilogy.
Both these literary references shift Faa in time. In The Raiders, Faa is placed as a contemporary in south-west Scotland with of Grierson of Lag during the Killing Times, while in His Dark Materials he is moved to southern England in an alternate, somewhat Steampunk universe into a time which is apparently contemporary with our own.