Rochester, town, SE England, on the Medway River, chief town of the borough of Medway, which also includes Chatham and Gillingham. Cement, heavy machinery, electronic equipment, precision tools, and clothing are made. In Roman times it was called Durobrivae; it was also important in Saxon times. St. Augustine founded a mission and bishopric there in 604, and Bishop Gundulf had a cathedral built on its site in the late 11th and early 12th cent. Most of the present cathedral is of 12th- to 14th-century construction. A Norman wall 12 ft (3.7 m) thick surrounds the ruins of a 12th-century castle, which was several times beseiged. King's School for boys was refounded in 1542. James II left Rochester in disguise in 1688. Charles Dickens's home at Gadshill is nearby.