ECGFRITH (d. 685)  , king of Northumbria succeeded his father Oswio in 671 . He was married to iEthelthryth, daughter of Anna of East Anglia, who, however, took the veil shortly after Ecgfrith's accession, a step which possibly led to his long quarrel with Wilfrid archbishop of York . Ecgfrith married a second wife, Eormenburg, before 678, the year in which he expelled Wilfrid from his kingdom . Early in his reign he defeated the Picts who had risen in revolt . Between 671 and 675 Ecgfrith defeated Wulfhere of Mercia and seized Lindsey . In 679, however, he was defeated by !Ethelred of Mercia, who had married his sister Osthryth, on the river Trent . Ecgfrith's brother IElfwine was killed in the battle, and the province of Lindsey was given up when peace was restored at the intervention of Theodore of Canterbury . In 684 Ecgfrith sent an expedition to Ireland under his general Berht, which seems to have been unsuccessful . In 685, against the advice of Cuthbert, he led a force against the Picts under his cousin Burde, son of Bile, was lured by a feigned flight into their mountain fastnesses, and slain at Nechtanesmere (now Dunnichen) in Forfarshire . Bede dates the beginning of the decline of Northumbria from his death . He was succeeded by his brother Aldfrith . See Eddius, Vita Wilfridi (Raine, Historians of Church of York, Rolls, Series, London, 1879-1894), 19, 20, 24, 34, 39, 44; Be e, Hist .

Eccl . (Plummer,

Oxford, 1896), iii . 24, iv . 5, 12, 13, 18, 19, 21, 26 .