A bishop of Lichfield, whose name was Ælfwine, was always called Ælla, and thus there is reason to suppose that elves named both the Ælle of Deira, whose name caused Gregory the Great to say that Alleluja should be sung in those regions, and also the later Ælla, who put Ragnar Lodbrog to death... (History of Christian Names, Yonge, 1884)

The first Saxon state, after that of Kent, which was established in Britain, was the kingdom of South-Saxony.  In the year 477, Ælla, a Saxon chieftain, brought over an army from Germany; and landing on the southern coast, proceeded to take possession of the neighbouring territory... (The History of England from the Invasion of Julius Caesar to the Revolution in 1688, Hume, v.1, 1889)