The code of Dunvallo Mulmutius, sixteenth King of the Britons (about B.C. 400). This code was translated by Gildas from British into Latin, and by Alfred into Anglo-Saxon. These laws obtained in England till the Conquest. (Holinshed: History of England, iii. 1.).
Mulmutius made our laws, Who was the first of Britain which did put His brows within a golden crown, and called Himself a king.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894