Chatham, town, Kent, SE England, on the Medway River. Chatham, Rochester, and Gillingham form a contiguous urban area that is now the unitary borough of Medway. Chatham was a major naval station, with well-equipped dockyards, dry docks, and shipbuilding and repairing equipment; these were ultimately closed by 1984. Some facilities have been preserved for historical and tourist interest; others have been redeveloped for residential or business use. The first dockyard was established by Elizabeth I in 1588. The Roman Watling Street ran through Chatham.