At the end of each Gospel there are colophons which identify the scribe and give some information about him. He is identified as Máel Brigte úa Máel Úanaig and he was writing in Armagh in his twenty-eighth year. Máel Brigte alludes to various contemporary events, such as the killing of Cormac Mac Cárthaig by Toirdelbach Ua Briain which allow the writing of the manuscript to be dated to 1138. Marginal and interlinear glosses and notes were added in the 13th century. The manuscript is decorated in Insular style. Although the high point of Insular style was centuries before the production of this manuscript, this manuscript is an example of the enduring appeal of the Insular style in Ireland. The decoration in the manuscript includes two full page miniatures of Evangelist symbols, the lion of Mark (folio 60) and the ox of Luke (folio 86). In both of the miniatures, the artist has solved the problem presented by placing horizontally oriented animals in the space of the vertically oriented page by turning the animals ninety degrees so that they seem to walk up the page. Both symbols are abstracted, placed against an abstract multi-colored background, and contained within a thick border made of decorated panels. There are also four large zoomorphic initials in the manuscript; at the beginning of the Nativity of Christ in the Gospel of Matthew (Matthew 1:18, folio 10r), and the beginning of each of the other Gospels (folios 61r, 87r, and 128r). There are smaller initials at beginning of each section of the prefatory material, and at important texts within the Gospel, including the Pater Noster in Matthew (folio 19r), the Magnificat in the Luke (folio 88r), and the beginning of the Resurrection sequence in Luke. Other initials in the manuscript are highlighted in color. All of the decoration in the manuscript is done in green, red, brown, and yellow washes. The manuscript was in the Bibliothèque du Roi in Paris by the early 18th century, when it was described as being part of library by Père Richard Simon in his "Bibliothèque critique" in 1708. It was stolen from the Bibliothèque du Roi in 1707, along with other manuscripts by Jean Aymon. Aymon took to Holland where it was purchased by Robert Harley. It remained part of the Harley Collection, which was purchased in 1753 by Act of Parliament and became one of the foundational collections for the British Library.