Brehon law
Prior to English rule, Ireland had its own indigenous system of law dating from Celtic times, which survived until the 17th century when it was finally supplanted by the English common law. This native system of law, known as the Brehon law, developed from customs which had been passed on orally from one generation to the next. In the 7th century AD the laws were written down for the first time. Brehon law was administered by Brehons (or brithem). They were the successors to Celtic druids and while similar to judges; their role was closer to that of an arbitrator. Their task was to preserve and interpret the law rather than to expand it.
In many respects Brehon law was quite progressive. It recognised divorce and equal rights between the genders and also showed concern for the environment. In criminal law, offences and penalties were defined in great detail. Restitution rather than punishment was prescribed for wrongdoing. Cases of homicide or bodily injury were punishable by means of the eric fine, the exact amount determined by a scale. Capital punishment was not among the range of penalties available to the Brehons. The absence of either a court system or a police force suggests that people had strong respect for the law.
The first encroachment on Brehon law came in 1155

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