Ælla , king of Northumbria - display name

I've removed the "II" from his display name as a perfunctionary search tells me there is only one Ælla of Northumbria

Kings of Northumbria 642–867

Oswiu Ecgfrith Ealdfrith Eadwulf I Osred I Coenred Osric Ceolwulf Eadberht Oswulf Æthelwald Moll Ealhred Æthelred I Ælfwald I Osred II Osbald Eardwulf Ælfwald II Eanred Æthelred II Redwulf Osberht Ælla