n.
Administrative (pop., 2001: 1,310,922), geographic, and historic county, eastern England.
It extends along the North Sea coastline between the estuaries of the Rivers Thames and Stour . Chelmsford , centrally situated, has long been the county headquarters and is also the seat of a church diocese. The ancient county stretched west as far as Middlesex , but Greater London now incorporates its southwestern corner. It was a Roman centre until the 5th-century Saxon invasions; it became one of the Anglo-Saxon kingdoms of the Heptarchy and had its centre at London. It came under Danish control in the 9th century and was later reconquered by Wessex . Despite its proximity to London, much of Essex remains rural, and the county is highly farmed; it is also the site of petroleum installations on the River Thames and of a nuclear power plant. The University of Essex is at Colchester.