 Its contents can be at least partially reconstructed via subsequent citation of the manuscript and a couple of descriptions of it; some material may well be reflected or, in some cases, preserved in later, still-extant manuscripts.Both medieval and modern scholarship often holds that the codex was compiled by Cormac mac Cuilennáin (died 908), bishop and king of Munster.However, it is now generally thought to have been produced under Brían Boruma (died 1014), king of Munster and aspirant king of Ireland, to justify and promote the claims of his own rising dynasty and region.