The Welsh are the people of the nation of Wales in the United Kingdom. The Welsh language is a Brythonic (as opposed to Gaelic) Celtic language that developed from the Old British language of the Britons who lived in Wales. By the eleventh century C.E. the Brythonic Celtic language had split into Welsh, Cornish (the language of Cornwall), and Breton (the language of Brittany in France). The Welsh produced a complex mythology that in many ways parallels that of Gaelic Ireland but that has a distinctive character, as seen in in the many Welsh tales of King Arthur.