The battle was a disaster for Northumbria. With both Edwin and his son Osfrith killed, and his other son Eadfrith captured by Penda (and later executed), the kingdom disintegrated. Eanfrith, a son of the former king Aethelfrith, returned from exile to seize power in one of the Northumbrian sub_kingdoms, Bernicia, while Edwin's cousin Osric took over the other sub_kingdom, Deira. Cadwallon continued to wage a war of ruthless slaughter against the Northumbrians, and was not stopped until the Battle of Heavenfield a year later.
The Battle of Hatfield (O.E. Haethfelth) was fought on October 12, 633
With both Edwin and his son Osfrith killed, and his other son Eadfrith captured by Penda (and later killed), the kingdom was divided between its constituent kingdoms of Bernicia and Deira.
Kirby suggested that the defeat of Edwin was the outcome of a wide-ranging alliance of interests opposed to him, including the deposed Bernician line of Æthelfrith; but considering the subsequent hostility between Cadwallon and Æthelfrith's sons, such an alliance must not have survived the battle for long.