He is said to have been king of Northumbria from 862 until his death in 867.
Not descending from the royal line, he shares the throne with his competitor Osberth.
The latter reigns over Bernicia and Aelle over the Deira (Anglo-Saxon Chronicle). and who had just taken York.
It was in front of York that Aelle and Osberth were defeated and killed by the Vikings on March 21, 867.
Aelle is said to have been executed by Ragnar Lothbrok's sons Ivar, Haldan and Ubba, who put him to the blood eagle to avenge the death of their father whom Aelle had thrown into a pit full of snakes.
It is for this purpose that the latter had invaded Northumbria according to the Norse sagas.
A/N:Revenge is always an "honorable" motive for an invasion in the eyes of posterity.
C.L.