Evan Ragland, immigrant ancestor and claimed to have royal blood through the Barons Bergavenny (aka Abergavenny).
The royal lineage from Edward III was claimed by a book called "Genealogies of the Ragland Families", by Margaret Miriam Hale Strong (1928). (Thanks to John Higgins for this source.)
However another work The Raglands - The History of a British-American Family, Volume I and II, by Charles Ragland, Jr, identified Evan Ragland's mother's ancestor James Morgan as base son of Sir Thomas Morgan, whose wife was Cicely Herbert. The claim to royal lineage arises from an allegation that Cicely Herbert were thusly James' mother (which was not claimed by Charles Ragland), not allowing for the higher likelihood that James were Thomas' natural-born son, whose mother were unknown.
The possibility that James Morgan were legitimately-born son of Sir Thomas Morgan, was disproved by Will Johnson on 24 Oct 2008 in a posting to soc.genealogy.medieval, "Re: Comprehensive descents from E3" citing this page to show that no James Morgan inherited from Sir Thomas, as a legitimate son would have in that situation.
The identification (by Charles Ragland Jr) of James Morgan being son of Sir Thomas, is not impossible but it remains to be positively attested, instead of the currently known weak identification.