The social structure of Iron Age Celtic society was highly developed. It was a tribal society that was bonded together by a complex system of laws and social customs. The established body of Law was known as ‘Fenechas’, the law of the Feine (Freemen), or more commonly, the Brehon Laws. This body served the People for centuries.
The most common body of Brehon Laws was codified in 438, by the order of Laighaire, a High King of Ireland. The proceedings by which this work was done by three Kings, three Brehona (Recitors of the Law), and three Christian missionaries. By this act Pagan Fil’ and Christian monks came together and worked out a set of laws that was workable for people of both religions. The body of that law has been transmitted to us in the volumes known as the Senchus Mor.
The body of Law known as Brehon Law, as contained in the Senchus Mor is a body of national law. However, national law was secondary to local law. Whether local or national it was the Brehons who acted as the recitors of the Law.
There has been some confusion about who acted as the judge. It was the nobility who acted as such. As stated the Brehons were the recitors of the Law. After the Brehon had recited the Law, only then could the King or Queen render a decision. This is why lore is replete with examples of the Kings or Queens Druid, actually the Ard-Fili, having the right to speak before the King.
If the Brehon, who was a member of the intellectual/skilled caste, recited the law incorrectly they were expected to forfeit their fee and pay damage costs. The Brehon laws were responsible for regulating how people interacted. Hospitality, etiquette and other things were set out in ways that left little room for doubt. The codes of behavior established in the Law was such that all members of a family had to adere to it.
Codes of behavior and levels of responsibility were laid down in the laws for each social group. The more responsibility a social group had, the more restrictions were placed on them. Status was determined by the ownership of cattle and a few other things. There was no concept of land ownership in early Celtic society. This stands in sharp contrast to the Roman and Anglo patterns.
Druids also carried out sacrifices of crops, animals, and during specific festivals, humans. In a Celtic society, people were not executed for crimes, except during these festivals. Such executions varied, depending on what god the execution was dedicated to. Among the most famous is the human sacrifices practiced in the course of Essus worship.
Essus was, more or less, a benevolent law god to many Celts, particularly Gauls. However, Essus worship also intoned a sense of merciless behavior toward repeated criminals, rapists, traitors, and other societal dregs. The offender, if found guilty, would be taken to the temple of Essus, where an oak would be growing through an opening in the temple roof. His stomach would be cut open, and he would be hung from an oak branch.