It is first mentioned in the Anglo-Saxon Chronicle under the date 605.The ealdorman, or sheriff, of the shire was probably charged with the duty of calling out and leading the fyrd, which appears always to have retained a local character, as during the time of the Danish invasions we read of the fyrd of Kent, of Somerset and of Devon.
In 991 the Danes burned Ipswich, and defeated and slew the East Saxon ealdorman Brihtnoth at Maldon.
The earldom in the 10th century apparently included several other counties, and its most famous holder was the ealdorman Brihtnoth, who fell at the battle of Maldon in 991.
The thegn, the ealdorman, the king himself, fought on foot; the horse might bear him to the field, but when the fighting 2 Du Cange, Gloss., s.v.
He bore the title not of king but of judge, a title which may be compared with that of ealdorman among the AngloSaxon invaders of Britain.