Just a little before King Alfred
The Molmutine Laws were established in Britain by King Dunvallo Molmutius (Welsh Dyfnwal Moelmud), according to Geoffrey of Monmouth. Dyfnwal Moelmud is referred to in Welsh tradition, predating Geoffrey’s work, as a lawmaker but there are no native sources for Geoffrey’s elaboration of that tradition.
One of the Molmutine Laws, according to Geoffrey’s account, declared that the temples of the gods and cities should act as sanctuaries from death. Furthermore, anyone who flees to a temple for being accused of a crime must be pardoned by the accuser upon departure from the temple. This law soon included all roads leading to temples and all farmers were declared safe from such crimes.
According to Geoffrey’s account, King Molmutius borrowed many of his laws from the Trojans who settled in Britain before him. One such Trojan/Molmutine law allowed the reign of queens.
Iolo Morganwgs triads
At the end of the 18th century or beginning of the 19th, antiquarian forgerer Iolo Morganwg claimed to have found a long list of Welsh triads giving the laws.
They include :
There are three tests of civil liberty; equality of rights; equality of taxation; freedom to come and go.
Three things are indispensable to a true union of nations; sameness of laws, rights and language.
There are three things free to all Britons; the forest, the unworked mine, the right of hunting.
There are three property birthrights of every Briton; five British acres of land for a home, the right of suffrage in the enacting of the laws, the male at twenty-one, the female on her marriage.
There are three things which every Briton may legally be compelled to attend; the worship of God, military service, the courts of law.
There are three things free to every man, Briton or foreigner, the refusal of which no law will justify; water from spring, river or well; firing from a decayed tree, a block of stone not in use.
There are three classes which are exempt from bearing arms; bards, judges, graduates in law or religion. These represent God and His peace, and no weapon must ever be found in their hands.
There are three persons who have a right of public maintenance; the old, the babe, the foreigner who can not speak the British tongue.
There are three things free to a country and its borders; the roads, the rivers and the places of worship. These are under the protection of God and His peace. (In this law originated the term The King’s Highway.)
 Dunvallo Molmutius (Welsh: Dyfnwal Moelmud) was a legendary king of the Britons as accounted by Geoffrey of Monmouth. He was the son of Cloten, the King of Cornwall, and he restored order after the Civil War of the Five Kings. He and his descendants were of a sub-branch of the genealogical line of Brutus, the dominant line having ended with Porrex I before the civil war.
Dunvallo was the King of Cornwall during the war created in the power vacuum left by Porrex I. He was braver and more courageous than all the other kings in the war. He defeated Pinner, the king of Loegria. In response, Rudaucus, king of Cambria, and Staterius, king of Albany, allied together and destroyed much of Dunvallo’s land. The two sides met in battle and were stalemated. Dunvallo then took 600 of his men and himself and dressed themselves in the armour of the dead enemies. They led a charge deep into enemy lines where they killed the two kings. After this battle, Dunvallo destroyed the remaining defences of the kings and pillaged their lands.
Following the defeat of the rival kings, Dunvallo created a crown like that of his predecessors and claimed the throne of Britain. He created a set of rules for the kingdom called the Molmutine Laws which lasted for many centuries. Also, robbery throughout the kingdom nearly ended for fear of Dunvallo and his laws. He reigned in peace and prosperity for forty years then died and was buried in the Temple of Concord, a tribute to his laws, which resided in Trinovantum. His death sparked another civil war between his two sons, Belinus and Brennius.