Essex is a county located in the south-east region of England's capital city, London. Located in the United Kingdom's home counties, it is bordered to the north by Suffolk and Cambridgeshire, east by Hertfordshire, and south and south-west by Greater London. The county is bordered to the north by Suffolk and Cambridgeshire, east by the North Sea, west by Kent across the estuary of the Thames, and south and south-west by Hertfordshire. Located at the county seat of Chelmsford, which is also the county's sole city. Essex is included in the East of England area for the purposes of government statistics.
The county of Essex may be defined in four ways, with the ancient county being the most expansive. The ceremonial county is the next largest, followed by the former postal county, with the administrative county being the smallest – the area administered by the County Government, which excludes the two unitary authorities of Thurrock and Southend-on-Sea, as well as the areas administered by the Greater London Authority.
The ceremonial county encompasses the eastern portion of what was formerly known as the Kingdom of Essex in the Early Middle Ages. In addition to rural regions, the county has London Stansted Airport, the new towns of Basildon and Harlow, Lakeside Shopping Centre, the port of Tilbury, and the borough of Southend-on-Sea.