Cornouaille ([kɔʁ.nwaj]; Breton: Kernev, Kerne) is a historical region on the west coast of Brittany in West France. The name is cognate with Cornwall in neighbouring Great Britain. This can be explained by the settlement of Cornouaille by migrant princes from Cornwall who created an independent principality founded by Rivelen Mor Marthou, and the founding of the Bishopric of Cornouaille by ancient saints from Cornwall. Celtic Britons and the settlers in Brittany spoke a common language, which later evolved into Breton, Welsh and Cornish.