Battle of the Books.

Probably the first copyright dispute in Ireland took place between St Columba or Colmcille and St Finian, Colmcille had borrowed a Palster and surreptitiously made a copy of it, when Finian found out he demanded the copy. Colmcille refused and the matter went to arbitration at the court of High King Diarmuid, who decided in favour of St Finian with the famous ruling 'To every cow its calf, to every book its copy.' Colmcille refused to accept the ruling and when Diarmuid killed a youth whom Colmcille had given sanctury, he persuaded his kinsmen the O'Neills to wage war on Diarmuid, the O'Neills were victorious at the Battle of Cooldrumman (Culdremna) north of Sligo in AD 561 which is reputed to have cost three thousand lives.

A Synod was held at Tailte, County Meath, at this Colmcille was ordered to convert a equal number of pagans. He moved to the island of Iona on the Scottish west coast, where he founded a monestary there he set about converting the Pictish tribes to Christianity, his actions were largely responsible for the foundation of the Scottish Kingdom of Dalriada which had close links with County Antrim.

It is possible that the Cathach a manuscript now preserved in the Royal Irish Academy in Dublin may be the book in question.