The Cornish language comes from the same branch of Celtic languages as Welsh and Breton. It started to develop as a separate language about 2000 BC and remained so until around the seventeenth century, when English became necessary. Slowly the Cornish language died out, with the last native speaker, Dolly Pentreath, dying in 1777, but it is starting to undergo a renaissance, with rumours of pending recognition as a regional language by Europe.
Like many Celtic peoples Cornwall abounds with stories of little folk, other beings lurking just beyond the fringes of civilisation, in the case of Cornwall piskies and Giants. It is tempting to see such stories as a record of the meeting of the Celts with the indigenous Bronze Age people, but are more likely to be simply corruptions of mythological stories.
Cornwall also has industry specific myths, the Knockers, for example, inhabited tin mines looking after the miners, and the shores are thronged with Mermaids, plaguing the fishermen.
The best known of Cornish myths, however, must be King Arthur. Although most parts of the British Isles lay claim to the great national hero, Cornwall is most obviously associated with him, with Tintagel, the castle where he was conceived, and even his surname, Pendragon, having a distinctively Cornish ring.
The Arthur myth also takes in the land of Lyonesse, said to lie sunken between Lands End and the Scilly Isles, drowned in a great storm in the eleven century.