Hey, blam, those tartans didn’t get from Central Asia to the Scottish highlands by themselves. :’)
VR, I think the last native speaker of Cornish died around 1900-1905.
I thought that Cornish died out in the 18th century but could be wrong. I think there is a group which is trying to revive it (as a second language) but they may have to fill in some bits from Welsh. (Sort of like using frog DNA for dinosaurs in “Jurassic Park”...)