Cornish: Ke; French: Ké
Kea was a British saint from the Hen Ogledd ('Old North') in the late 5th century. He is known through an incomplete play from the 16th century, Beunans Ke ('The Life of St. Ke') which is to be found in the National Library of Wales. He is also known through a lost Latin hagiography written in the 17th century by Maurice of Cleder.
He is said to be the son of a king named Lleuddun Luyddog of Lothian, serving as a bishop in North Britain before he became a hermit. From Scotland he went to Wales and then further south, and he founded churches at Street, Somerset and Landkey in Devon. He settled in Cornwall in a place which subsequently was named Kea, after him. The Cornish king, Teudar, was hunting a deer, which Kea sheltered, and for this the king harassed him by confiscating his oxen. Kea then plowed his soil by using the deer. He later traveled to Cleder in Brittany, where he eventually died.
Kea was called from Brittany before the battle of Camlann to negotiate a peace between Mordred and his uncle, King Arthur, but arrived too late. He criticized Guenevere for her adultery with Mordred and persuaded her to take the veil.
There's a section in Beunans Ke which describes Arthur's conflict with Lucius Hiberius, the Roman emperor, and Mordreds subsequent treachery.