Researching one of my girlfriend's ancestors, I came across a man who seems to be the progenitor of the family. He lived through the 15th century, was lord of a 'barton' (demesne, or part thereof) in Cornwall, had a number of children married into nearby noble families, those children also appear in records as gentlemen and successive descendants as gentlemen and esquires, the family also had a coat of arms. When the heraldic visitations came to town in 1620, though, the progenitor's son was declaimed and declared ignoble (if I am correct, this would indicate he could not prove three generations of noble lineage). The family name appears in no records (at least those I can access online) prior to the progenitor's appearance on the scene and can't be found beyond Cornwall for at least three-four generations. Additionally, there are no places in Cornwall or anywhere else that match the name (as far as I know).
Is it possible that this guy could have invented a name to go with a purchased claim to nobility? Does anybody know of similar instances or examples?
Cheers!
In a lot of Europe, arms were unregulated. You could adopt whatever arms you liked.
In England, the strict regulation of bearing of arms happened well after the start of heraldry -- the English College of Arms itself was founded by Richard III. I don't know when Scotland started its regulation, but it's the strictest jurisdiction today: it's actually a punishable offence to bear arms without leave of Lyon King of Arms, and Lord Lyon has a court where they'll cheerfully prosecute you (which is why he's Lord Lyon -- "Lord" as in "milud", as in a senior judge).
After strict regulation started in England, you can get arms granted by the College of Arms, but you do have to pay substantial fees and show cause why you are prominent enough to deserve them. (That requirement continues today, but criteria like "attended a university" make the bar somewhat lower.)
In England and Scotland, there is no connection between a surname and the coat of arms. They are not the Rogering-Tosspot coat of arms, where any Rogering-Tosspot could bear them. They are the coat of arms of a particular Mr. Falstaff Rogering-Tosspot over in Nussex, who inherited them from Henry R-T, who inherited them from ... So those "bucket shops" in shopping malls selling "your coat of arms" are fraudsters. See the two FAQs under http://www.heraldica.org/here.htm#common%20questions for more information. Exception: Poland did have some sort of scheme for shared surnames, which I'd have to look up.
"Declaimed and declared ignoble" doesn't look right. I think you mean that the arms were "defaced", mutilated so as not to look like arms. "Noble" is rather a restricted concept in England. I don't know that three generations of anything were required; I have the impression that it was something of a judgment call as to whether they were "gentry" (itself a very vague concept, never legally defined) or that you've borne them from time out of mind (so some ancestor might have invented them ad hoc). Would you like me to look around more on these points?
It has been quite common over the centuries for people to use coats of arms which they have no official right to, not always wittingly, people may assume that having a certain surname or family history entitles them without realising the strict rules which underpin the system.
In English Heraldry this has normally revolved around proving a direct line of male-descent to the original legitimate bearer of the arms, although descent on the female line is also sometimes used - but bear in mind that men and women bear different arms as the designs are gender specific, so a daughter can not have the same arms as her father.
There aren't any conclusive lists of the individuals and families with the right to bear arms before the 1680s, but you may be able to dig something up by consulting this source; Harleian Society, vol. 66, 1915 which has a compiled list of known Grantees of Arms prior to this date. It is not a complete list as it only contains those whose records survived. You would be very lucky to find anything at all really, even if the use was legitimate, before the incorporation of the College of Arms in the 1480s.
As to whether a person could pay, there is a fee involved in a Grant of Arms, but if the rules were being followed the Grantee would still have to fulfil the necessary requirements.
You can also consult the College of Arms, who have in-house genealogists, this may be costly though.
http://www.college-of-arms.gov.uk/services/proving-a-right-to-arms