In the latter part of the seventh century the power of the Anglian kingdom of Northumbria reached its height. Upon its northern frontier, over against the Picts, a vigorous forward policy was adopted; and here, as so often in our early history, the Roman Church revealed herself as the ally of the State. Some part of the Pictish borderlands, south of the Forth, had by this time passed under Northumbrian control; and on the strength of this an Anglian churchman, Trumwin, was planted in 681 at Abercorn, with the portentous title of ‘Bishop of the Picts’. The Northumbrian Church thus intruded at Abercorn has left its monuments today in a hog-backed stone and some cross shafts, one of great beauty showing among its enrichments the characteristic Anglian vine-scroll. These ecclesiastical measures were the prelude to an invasion of Pictland on a great scale, upon which the whole power of the Northumbrian kingdom was bent under its able and warlike monarch, Egfrith. But the High King of the Picts, Brude MacBile, proved himself equal to the crisis. At the famous battle of Dunnichen, or Nechtan's Mere, on Saturday, 20th May 685, he utterly destroyed the Anglian army of invasion—Egfrith and the flower of his nobles being numbered among the slain. This memorable victory dealt a blow at the power of Northumberland from which that haughty and resplendent kingdom never recovered; and its rapid military, political, spiritual, and moral decline is rightly dated from that event.