'Howel Da o rat Duw, mab Kadell, brenhin Kymry oll...'
'Hywel Dda by the grace of God, son of Cadell, king of the whole of Wales...'

The Law of Hywel, attributed to king Hywel ap Cadell (Hywel the Good), d. 950, was the legal system which applied to all of Wales throughout the middle ages until it was abolished by the Acts of Union in 1536. Written by lawyers for lawyers, the legal system was based on compensation for injury or loss, rather than punishment, and stressed mutual responsibility. The law is preserved in over 40 manuscripts, dating from c.1250 to the sixteenth century, and the manuscripts are lengthy prose texts, rich in technical vocabulary in middle Welsh.

Cyfraith-Hywel.org.uk focuses on research on the manuscripts of Welsh law. Dr Sara Elin Roberts led the original research project, which was funded by the University of Wales and the Coleg Cymraeg Cenedlaethol. This site presents the contents of all of the manuscripts of Welsh law in the form of related and searchable databases. There is also a full bibliography of works on Welsh law, and texts and information on Ancient Laws, the first full study of the laws published in 1841.

Dr Sara Elin Roberts is a historian specialising in the law, literature and culture of medieval Wales and the March from the twelfth to the fifteenth century. As a leading authority on Cyfraith Hywel she has published widely on the subject, including several editions of Welsh law manuscripts. She is a well-known lecturer and regular contributor to BBC Radio Cymru on various medieval subjects.