A few years ago, (long before I discovered this website,) I was browsing some of those fake "buy your family arms" sites. I noticed that under Thompson, they usually had three varieties:
the familiar red cabossed stag's head with devices on a blue chief for Scotland;
the black-and-silver three falcons with the counter-embattled divider for England; and
the three estoils with the sun-canton for Ireland. Nice and neat. If only it was that easy!
I had done some research in a book called The Enclyclopaedia of Heraldry, or the General Armorie of England, Scotland, and Ireland. (Published 1844, available on Google Books, and quite an interesting read in its own right!)
I had found about 44 variations of Thoms listed. When I separated the varieties of matriculations out, nine were the stag's-head motif, seven were the three-falcons motif, and four were the sun-in-canton motif. True to form, the Stag's-Heads were Thomsons, and the Three-Falcons were Thompsons. Surprisingly, ten were some version of a lion passant/sajant, and a further ten were chevron-dividing-three-bits (escallops, estoils, crescents, or whatnot.) There were also some oddballs, like an eagle displayed, or a seahorse holding a flag.
Is this indicative that these are completely separate lines of Thompsons? I suspect that Lord Lyon, the Garter King of Arms, and Ulster King of Arms all do things differently. Could the Non-Stag Thompsons be borderers who fled to England and were granted English arms, and the Sun-Canton Thompsons descendants of displaced Ulsterers? Or are they completely different Sons of Thom than Thomson of That Ilk? Or were they granted arms by England a propos of no previous arms at all?
I think I understand that Lyon may grant a differenced arms to anyone of the same family name, whether or not they can prove direct lineage. Does England work on a different system; that if you can't prove lineage your arms are unique? That would certainly explain the huge variety of English Thompson arms. ...Right?
This armiger stuff is very interesting...the more I learn, the more I want to know!
--Bill.