Mael Brigte's Gospels, BL MS Harley 1802, a manuscript written at Armagh in the twelfth century, is datable from reference in its colophons to the killing of Cormac Mac Carthaig, king of Munster and of Ireland. The date was first worked out as 1139 from unpublished annals by Humfrey Wanley (1672-1726), Harley's librarian, in 1713-14, in a remarkable piece of scholarship. Wanley understood the importance of a dated manuscript as a basis for palaeographical judgement of undated books. The manuscript and, almost certainly, Wanley's discussion came to the notice of John O'Brien (1701-1769), bishop of Cloyne, who saw the manuscript in the British Museum in 1767. Using the so-called
Dublin Annals of Inisfallen, compiled for him by Fr John Connery, O'Brien was able to refine the dating to 1138, and he added a discussion of this colophon when he prepared his
Focaloir for the press in 1767-8. The tenor of one colophon's reference to Cormac's killing is interpreted as itself significant: from the perspective of the all-Ireland primatial see where Mael Brigte wrote, the killing of King Cormac ended hope of a faithful all-Ireland monarchy. The colophon can be read as a contemporary judgement.
(source: Oxford University Research Archives)