In AD 824, following the Battle of Ellandun, the kingdoms of the East Saxons, the South Saxons and the Kentish were absorbed into the kingdom of the West Saxons, uniting Saxland under King Alfred's grandfather Egberht.
In changes before the Norman conquest the East Saxons were subsumed into the Kingdom of England and, following the Norman conquest, Essex became a county.
During the medieval period, much of the area was designated a Royal forest, including the entire county in a period to 1204, when the area "north of the Stanetreet" was disafforested.
It borders the counties of Suffolk and Cambridgeshire to the north, Hertfordshire to the west, Kent across the estuary of the River Thames to the south and London to the south-west.
The county town is Chelmsford, which is the only city in the county.
Essex occupies the east of the pre-England Kingdom of Essex.
As well as rural areas, the county also includes the Lakeside Shopping Centre, London Stansted Airport and the new towns of Basildon and Harlow.
The name Essex originates in the Anglo-Saxon period of the Early Middle Ages and has its root in the Old English Ēastseaxe (i.e.