Essex is a ceremonial and non-metropolitan county in the East of England, and one of the home counties. It is located to the northeast of Greater London. It borders with Cambridgeshire and Suffolk to the north, Hertfordshire to the west, Kent to the South and London to the south west. Essex County Council is the principal local authority for much of the county, sharing functions with twelve district councils. The county town is Chelmsford. The southern Essex boroughs of Thurrock and Southend-on-Sea are governed separately as unitary authorities. It was established in antiquity and formed the eastern portion of the Kingdom of Essex. Sections of the county closer to London are part of the Metropolitan Green Belt, which prohibits development. It is the location of the regionally significant Lakeside Shopping Centre and 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. the "East Saxons"), the eastern kingdom of the Saxons. Originally (in 527 AD) it occupied territory to the north of The River Thames, incorporating all of what later became Middlesex and most of what later became Hertfordshire, though its territory was later restricted to lands east of the River Lea.Colchester in the north east of the county is Britain's oldest recorded town, dating back to before the Roman conquest, when it was known as Camulodunum and was sufficiently well-developed to have its own mint. Subsequently the Kingdom of Essex was subsumed into the Kingdom of England and Essex eventually became a county.