Reputed to be the site of an early ecclesiastical Columban monastic site associated with the Cathach of St. Columba (Colmcille), which was the subject of the oldest known case of copyright law.  The Cathach is a book of psalms, and was kept for centuries in Ballymagroarty.  During the eleventh century, Cathbharr Ó Domhnaill, chief of the O'Donnells and Domhnall Mag Robhartaigh, the Abbot of Kells commissioned a special shrine (cumdach) for the Cathach.  The shrine and book were borne into battle to inspire the O’Donnell Clan to victory. The book is Ireland's oldest illustrated manuscript and reputed to be the second oldest in the world.  It may be viewed at the Royal Irish Academy, Dublin.