From Warlinenn: http://www.cornish-language.org/English/faq.asp
There was a keen hunt in the eighteenth century to find the 'last'
speaker. But this was no-more than an ego-trip by some linguists. By the
time the last native speakers were dying out, the revival had begun. So
essentially, the language never actually died out.
Also,
Where is the Cornish Language spoken?
In the year 1200, Cornish was spoken my most people over most of
Cornwall. By 1600, it had been pushed west to Bodmin by Anglicisation. A
hundred years later in was not found very much east of Truro and by
1777, when the last monoglot speaker (Dolly Pentreath) died, it was
confined to West Penwith and areas of the Lizard peninsula. Speakers of
Cornish with native knowledge of the tongue could still be found up
until the late nineteenth century.
