The shrine belonged to the Chiefs of Clan Ó Domhnaill, the Lords of Tír Chonaill, as a rallying cry and protector in battle.

[1] Today the manuscript (RIA MS 12 R 33) is in the Royal Irish Academy in Dublin and the cumdach is in the archaeology branch of the National Museum of Ireland.

He placed the Cathach in a silver case and deposited it for safety in a Belgian monastery, leaving instructions in his will that it was to be given up to whoever could prove himself Chief of Clan O'Donnell.

The Cathach written for the most part by a single scribe who used a book hand of round lettering and strong Latin or wedge-serifs on the upright strokes.

[12] According to the historian and calligraphier Timothy O'Neill, the scribe employed an edged rather than pointed quill, which he held at a flat angle "to produce thick downstrokes and thin horizontals".

[1][10] The specially made cumdach (book shrine) comprises an oblong, hinged wooden box covered with decorative bronze and gilt-silver plates, with mounts holding glass and crystal settings.

A new main face in gilt repoussé was added between 1350 and 1375 with a large seated Christ in Majesty flanked on the right by a Crucifixion scene, and by a saint (likely Columba) on the left.

[5] The cumdach has been in continuous use since its earliest construction, including by its hereditary keepers, the Magroarty family, of Ballymagrorty, County Donegal, one of whom was killed in 1497 when the shrine was captured.

[17] Written in Irish and placed clockwise along the borders of the reverse of back of the shrine (beginning at top-left), they are signed by its goldsmith, Sitric Mc Meic Aeda (Sitric, son of Meic Aeda), who records that he built the shrine under the instruction of Domnall Mac Robartaigh (an abbot at Kells who had retired before his death in 1094, but is described in the inscription as "successor of Kells”),[18] who in turn was under the commission and payment of Cathbarr Ua Domnaill.