Richard Carew died (6/11/1620)

Cornish translator and antiquary, born 1555 at East Antony.
Best known for his _Survey of Cornwall_ (1602). But our linguistic interest is in "An Epistle concerning the Excellencies of the English Tongue" (1605). He praises English as being, not just as good as Latin, but better. Crystal quotes a passage in which he extols the copiousness of the English vocabulary, by listing 30 different ways to say "Go away!"
There was a lot of this about in those years -- Nebrija's grammar and dictionary of Spanish (1490s, the first of any modern European language); du Bellay's _Défense et illustration de la langue française_ (1549) -- just to name a couple I've heard of -- all asserting the worth of modern languages as objects of study, as vehicles for literature and statesmanship -- against the exclusivity of Latin.
The Epistle is here:
https://www.bartleby.com/lit-hub/elizabethan-critical-essays/the-excellency-of-the-english-tongue-15956/
also online as an appendix to the _Survey of Cornwall_, which is how it was first published.
I didn't find anything about whether Carew himself actually spoke Cornish, or wrote anything in it.
https://en.wikipedia.org/wiki/Richard_Carew_(antiquary)