The earliest event of Irish history that bears a well authenticated date is the mission of Palladius to Ireland in A.D. 431. The record of this year is found in the contemporary chronicle of Prosper of Aquitaine. In another work written a few years later. Prosper writes of the institution of a christian church in Ireland by Pope Celestine, who died in 432. All the early Irish sources agree in dating the mission of Patrick in 432.

Seven years later, the Annals of Ulster and the Annals of Inisfallen have the entry, derived from an earlier common source: ‘ Secundinus, Auxilius, et Iseminus mittuntur in Hiberniam in auxilium Patricii ’ A short tract copied in the Book of Armagh and dating probably, like the other documents in the same collection, from about 700, tells that Auxilius and Iserninus were sent by Germanus. It is silent regarding Secundinus.

Over a century ago the Rev. Charles O'Conor published in his corpus of Irish historical writers a collection of annals, the authorship of which he ascribed to a certain Tigernach ua Braein, abbot of Clonmacnois, who died in the year 1088. This ascription O'Conor apparently adopted from Sir James Ware, and it is not unlikely that Ware took it from the learned Irish scholar Dubhaltach mac Firbhisigh who was in Ware's employment. Mac Firbhisigh probably had good reason for describing Tigernach as abbot of Roscommon as well as of Clonmacnois. There had been for centuries a close connexion between the two monasteries, and both were favoured with the protection of the kings of Connacht. For the rest, government of more than one monastic community by the same individual was quite common. Ua Braein was one of the family names of the sept of Clann Murchada, which is mentioned several times in the Irish annals and elsewhere.

Arthur Young's judgment on Irish roads is well known; that indefatigable traveller who had many hard words for the highways of his native country, asserted: ‘ For a country so very far behind us as Ireland, to have got suddenly so much the start of us in the article of roads, is a spectacle that cannot fail to strike the English traveller exceedingly ’ A quarter of a century later his views received general corroboration from the statistical surveys of the counties and from other commentaries and travel-journals of the time. Sampson, who found little to criticise in the county Derry roads, remarked: ‘ I have seen no country more intersected by good roads than the neighbourhood of Kilrea and Magherafelt’.