The Book of Aicill relates to the criminal law and is often discussed as being on par in significance with the Senchus Mór; although, the latter deals with civil law.
Like the mystery of Saint Patrick’s posthumous authorship of the Senchus Mór, the Book of Aicill attributes its authorship to that of the legendary Cormac MacArt who is supposed to have ruled as High-King of Ireland during the 3rd century AD, however, the text itself is claimed to be an expansion of Cormac’s earlier work by a monk named Ceannfalad who lived, much later, during the 7th century.
It could be viewed as early Ireland’s criminal code but this requires some elaboration because the view of a ‘criminal’ and what constitutes a ‘crime’ was hugely distinct from our modern understandings of these terms. Under the brehon laws a “wrong” varied in degree of seriousness according to the level of intention or forethought behind the act. Today, “crimes” are defined as a wrongful act against society (as a whole) that carries penal consequences.
