Essex, county (1991 pop. 1,495,600), 1,520 sq mi (3,938 sq km) SE England, on the Thames River and the North Sea, one of the "Home Counties" of London. Chelmsford is the county seat. The land rises from the low, irregular coastline to undulating pastoral country. Streams and salt marshes are plentiful. The chief crops of Essex are wheat, barley, sugar beets, potatoes, fruits, and vegetables. There is market gardening for London and some dairy and sheep farming. Oyster fisheries are also important. Industries include petroleum refining, chemicals, machinery, textiles, cement, processed foods, electrical goods, and nuclear power generation. Essex was once part of the kingdom of the East Saxons; Roman and Saxon remains are at Colchester and Maldon. Popular resorts line the coast.