Alt Clut
The ruler of Alt Clut was King Cynan, who had ruled since 798 and would continue to do so until 816.
Dál Riata
The ruler of Dál Riata at this time was likely to have been King Achaius mac Áeda Find.
Dumnonia
The ruler of Dumnonia during this time was either King Hernam ap Oswallt or King Hopkin ap Hernam, the exact year of the succession is unknown.
Gwynedd
The ruler of Gwynedd was King Cynan ap Rhodri (Cynan of Dindaethwy), who had ruled since 798 and would continue to do so until 816.
Mercia
The ruler of Mercia was King Cœnwulf, who had ruled since 796 and would continue to do so until 821.
Northumbria
The ruler of Northumbria was King Eardwulf, who had ruled since 796 and would continue to do so until 806.
Fortriu
The ruler of Fortriu was King Caustantin, who had ruled since 789 and would continue to do so until 820.