Though their ancestors had been pirates as fierce as the vikings of the 9th century, and though some of their later kings had led naval armamentsEdwin had annexed for a moment Man and Anglesea, and Ecgfrith had cruelly ravaged part of Irelandyet by the year 800 they appear to have ceased to be a seafaring race.
From this time onwards the Humber formed the boundary between the two kingdoms. In 684 we hear of the first English invasion of Ireland, but in the following year Ecgfrith was slain and his army totally destroyed by the Picts at a place called Nechtansmere (probably Dunnichen Moss in Forfarshire).
Were reckoned the chief monarchs of England, and exercised a widespread influence over the southern realms, yet each had to win his supremacy by his own sword; and when Edwin and Oswald fell before the savage heathen Penda, and Ecgfrith was cut off by the Picts, there was a gap of anarchy before another king asserted hh superior power.
In 660 he married his son Ecgfrith to ZEthelthryth, daughter of the East Anglian king Anna.
But Oswio and his son Ecgfrith greatly extended their territories towards the north and north-west, making themselves masters of the kingdoms of Strathclyde and Dalriada, as well as of a large part of the Pictish kingdom.
AEthelred married Osthryth, the sister of Ecgfrith, king of Northumbria, but in spite of this connexion a quarrel arose between the two kings, presumably over the possession of the province of Lindsey, which Ecgfrith had won back at the close of the reign of Wulfhere.