Almost 84,000 people across the country have declared their nationally as Cornish, the 2011 Census reveals – including a lone individual living in Gateshead.
While around 73,000 of them hail from Cornwall itself, more than 10,000 are scattered across England and Wales – from the North East to neighbouring Devon.
Campaigners calling for recognition of Cornwall as a nationality and greater devolution to the western peninsula hailed a huge surge in Cornish identity since just 37,000 did so in 2001, when the last Census was taken.
The figure is also remarkable, they say, because there is no tick-box for people responding to the Census to say they are "Cornish". Instead, they had to tick "other" and then write in their response.
North Cornwall Liberal Democrat MP Dan Rogerson said: "It is clear that many more people would have identified themselves as Cornish if there was a box to tick."
A Cornish diaspora also emerges. In London, 1,215 people are at least part-Cornish. The North East boasts 87 Cornish nationals.