King of Northumbria (867)
Sometimes known as Aelle II, by virtue of the fact that there was previously a sixth century king of Deira also known as Aelle
According to the Anglo-Saxon Chronicle he had no natural claim to the throne of Northumbria but simply seems to have been chosen to rule after the Northumbrians threw out Osberht in the year 867.
Later that year the Viking 'Great Army' led by Ragnarr Lothbrok's sons Ivarr the Boneless and Halfdan crossed the Humber and occupied York. Faced with this common enemy Aelle and Osberht put aside their differences and gathering their forces sought to retake York. As the Anglo-Saxon Chronicles relates,
having collected a vast force, with which they fought the army at York; and breaking open the town, some of them entered in. Then was there an immense slaughter of the Northumbrians , some within and some without; and both the kings were slain on the spot.
The survivors made peace with the Viking army, who proceeded to rule Northumbria through the medium of a sequence of puppet kings until the year 878 when they ended the pretence and established their direct rule with the formation of the kingdom of Jorvik.
Sic transit gloria mundi. So ended the kingdom of Northumbria.
SOURCES
A Biographical Dictionary of Dark Age Britain by Ann Williams, Alfred P. Smyth and D. P. Kirby (Seaby 1991)
Historia regum Anglorum et Danorum by Simeon of Durham
The Anglo-Saxon Chronicle