battle of Winwæd River

Winwæd River, battle of, 655. Here Oswiu of Bernicia successfully challenged the overlordship of Penda of Mercia and was able to take temporary control of Mercia and permanent control of Deira. Penda was killed in the battle and many of his supporters drowned when they tried to escape across the flooded river. The battle would have taken place near the Mercian/Northumbrian border.