Until the late 18th century, the shrine held a now-lost companion text, presumed to be a small illuminated gospel book associated with Saint Laisrén mac Nad Froích (d. 564 or 571), also known as Molaisse or "Mo Laisse".

In the 6th century, Molaisse founded a church on Devenish Island in the southern part of Lough Erne in County Fermanagh, with which the cumdach is associated.

This included embossed silver plates, a front piece depicting a cross, the figures and symbols of the evangelists, and series of Latin inscriptions.

The cumdach was held by the hereditary keepers O'Meehan family of Ballaghameehan, County Leitrim until the mid-19th century, and was acquired by the Royal Irish Academy in 1861, an acquisition supported by Lord Dunraven and George Petrie.

The Soiscél Molaisse was constructed in three phases: the rather plain 8th-century wooden core has bronze casing that once held a small illuminated manuscript.

[3] This book is assumed to have been a Gospel and was traditionally associated with the 6th-century Laisrén mac Nad Froích, also known as St. Molaisse (d. 564 or 571), who founded the church on Devenish Island on Lough Erne in County Fermanagh, where the shrine was kept.

[4] The island still contains the remains of the monastery site, including the small Teampall Mór church, his cell, and the round tower in which the Soiscél Molaisse was kept over the centuries.

[7] The 11th-century inscriptions on one of its long sides are signed by the metalworker Gilla Baíthín, along with the names of its commissioners "Cennfailad" (d. 1025, a successor of Molaisse who was an abbot at Devenish from 1001),[a][9] and "Ua Sclan" (unidentified, possibly an administrator at the island).

The dating of this phase to between 1001 and 1025 is based on the mention of Cennfailad,[10] making it the oldest-surviving fully intact cumdach or "book shrine" (an elaborate ornamented metal reliquary box or case used to hold Early Medieval Irish manuscripts or relics).

[10] It is similar in size, type and function to the extant shrine for the 8th-century Book of Dimma, although the casing is much thicker, suggesting that it had either contained additional texts to the Gospels or had more illuminated pages.

Until the early 19th-century, the book was thought to have been written or owned by St. Molaisse; one late medieval text describes how it was "sent down to him from heaven while on a pilgrimage to Rome".

It was enshrined in the early 11th century with a cumdach made up of plain sheets of tinned bronze decorated with openwork silver and mountings.

The Evangelists are depicted in profile or full front,[6] standing behind large angular ribbons,[9] and their names and representative figures are inscribed in Latin on each side of their silver frames.

[22] Matthew wears a knee-length tunic containing a row of shields (peltae) in the La Tène style, positioned above a wide hem.

[9] Mark is shown in profile with large, animalistic teeth and donkey-like ears, and also wears a half-length tunic with interlocking scrolls.

[10] It also contains triquetra (triangular figures composed of three interlaced arcs) knots and a zoomorphic lizard "whose head is formed with very long ears [that resemble] horns".

[38][39] Ua Scannlain was a cleric at Devenish, but although he fits the location and period, his full name is too long for the gap in the lettering and it is very unlikely he would have been mentioned by surname only.

[40] Other potential clerics are Scannlain Ua Dungalaín, abbot of Downpatrick, who was "abducted and blinded in 1010", and Scanlan Mac Cathail, ri Eoganacht of Lough Leane, although neither are considered strong candidates by most art historians.

[38] The Irish painter and antiquarian George Petrie claimed to have rediscovered the object, which he titled "The Shrine of Saint Molash", having read a local newspaper article about it c. 1835.