St. David of Wales, Feast Day and Welsh National Day, 1st March - David ( the Anglicised version of the Welsh ‘Dewi’) was born in the British Isles.David is said to have been of royal descent. On his father’s side he was linked with a Welsh prince and his mother was a niece of King Arthur. Born in South West Wales, in the late fifth or early sixth century and became a missionary travelling through Wales, England and Brittany, converting the pagan Celts of western Britain to Christianity.