Ancient remains have been found in the area around Rochester. The town has been occupied by Celts, Romans, Jutes and/or Saxons. In the Celtic era it was one of the two administrative centres of the Cantiaci tribe. During the Roman invasion of Britain a crucial battle was fought at the Medway close to Rochester. The first bridge was then constructed early in the Roman period.
During the later Roman era the area was walled in stone. King Ethelbert of Kent set up a legal system which has been maintained in the 12th century Textus Roffensis. In AD 604 the bishopric and cathedral were founded. During this era, from the recall of the legions until the Norman Invasion in 1066, Rochester was sacked about twice and besieged on a separate occasion.
The medieval era saw the construction of the current cathedral, the building of two castles and the founding of a significant town. The simple street plan was formed, constrained by the river, Watling street, the castle and the priory.
Rochester has given us two martyrs: St John Fisher, who was executed by Henry VIII because he refused to condone the divorce of Catherine of Aragon and Nicholas Ridley, executed by, Henry’s daughter, Queen Mary I as an English Reformation martyr.
Rochester was raided by people from the Netherlands as part of the Second Anglo-Dutch War. The Dutch, under the command of de Ruijter, broke through the chain at Upnor and sailed to Rochester Bridge capturing and firing the English.
The ancient city of Rochester in the heart of Kent combined with the borough of Chatham and part of the Strood Rural District in 1974 to form the Borough of Medway. It was later redubbed Rochester-upon-Medway, and the city status transferred to the whole borough.
In 1998 another merger with the other Medway Towns created the Medway unitary authority. The outgoing council neglected to elect ceremonial "Charter Trustees" to continue to represent the Rochester city, causing Rochester to forgo its city status.