Essex, one of the early kingdoms of Anglo-Saxon England. It was settled probably in the early 6th cent. by Saxons who traced their royal line back to a continental Saxon god instead of to Woden, as did the rulers of other early kingdoms. Essex eventually included the modern counties of Essex and Middlesex, most of Hertfordshire, and London. Under the influence of his uncle, Æthelbert of Kent, King Sæbert of Essex accepted (c.604) Christianity, but the kingdom lapsed into heathenism when his successors expelled (617) Mellitus, bishop of London. In c.653, however, at the request of King Sigbert, Oswy of Northumbria sent Cedd to convert the East Saxons and to build churches. The submission of Essex to the overlordship of Wulfhere of
Mercia marked the beginning of a long domination by the larger state. In 825, Essex joined other eastern kingdoms in submitting to Egbert of Wessex and became an earldom. Heavily settled by the Danes, it became part of the
Danelaw by the treaty of 886, but was retaken by Edward the Elder of Wessex in 917. Its most famous later earl was
Byrhtnoth, who was killed in the battle of Maldon in 991.
