616 Battle of the River Idle

Described by Bede in his Historia Ecclesiastica of 731.

East Anglia

Raedwald King East Anglia [46]

Northumberland

616 Æthelfrith King Bernicia, King Deira killed

12 Oct 633 Battle of Hatfield Chase

Gwynedd and Mercia

Penda King Mercia

Northumbria

Edwin King Bernicia, King Deira [47] killed

Eadfrith Deira captured

Osfrith Deira killed

634 Battle of Heavenfield

Northumbria

Osric King Deira killed

Oswald King Northumbria [30]

Gwynedd

05 Aug 642 Oswestry: Battle of Maserfield

Mercia and Powys

Eowa King Mercia killed

Penda King Mercia

Northumbria

Oswald King Northumbria [38] killed

654 Battle of Strath Ethairt

Dál Riata

Dúnchad mac Conaing King Dál Riata killed

Battle of Bulcamp

Anna King East Anglia killed

Jurmin Wuffingas killed

15 Nov 655 Cock Beck: Battle of the Winwaed

Northumbria

Oswiu King Bernicia [43]

Æthelwald King Deira withdrew his forces

Mercia

Penda King Mercia killed

671 Battle of the Two Rivers

Source: Stephen of Ripon's Vita Sancti Wilfrithi.

A decisive victory of the Northumbrians extending their territory up to the Firth of Forth.

Northumbrians

Beornhæth Sub-King Northern Northumbria aka Lothian

Ecgfrith King Deira, King Northumbria [26]

Picts

Drest VI King Picts

679 Lindsey: Battle of the Trent

A victory for the Mercians. Thereafter the Northumbrians lost their influence soth of the Humber, permanently returning the Kingdom of Lindsey to the Mercians.

Mercia

c 679 Æthelred King Mercia

20 May 685 Dunnichen: Dun Nechtain

Picts

Bridei III Picts [57]

Northumbrians

Ecgfrith King Deira, King Northumbria [40] killed

715 Adam's Grave: Second Battle of Woden's Barrow

Ine King Wessex

Ceolred King Mercia

Wessex

Unknown