It was, until 1998, The Romano-British name for Rochester was Durobrivae, later Durobrivis c. The two commonly cited origins of this name are that it either came from "stronghold by the bridge(s)" Durobrivis was pronounced 'Robrivis.
In later times, the word cæster (=castle, from Latin castrum) was added to the name and the city was called Robrivis Cæster. 730 and calls it Hrofes cæster, mistaking its meaning as Hrofi's fortified camp. 730 Hrofæscæstre, 811 Hrofescester, 1086 Rovescester, 1610 Rochester.
In AD 604 the bishopric and cathedral were founded.
In the 1835 Municipal Corporations Act the boundaries were extended to include more of Strood and Frindsbury, and part of Chatham known as Chatham Intra.
Like many of the mediaeval towns of England, Rochester had civic Freemen whose historic duties and rights were abolished by the Municipal Corporations Act 1835.
Rochester and its neighbours, Chatham and Gillingham, Strood and a number of outlying villages form a single large urban area known as the Medway Towns with a population of about 250,000.
These places nowadays make up the Medway Unitary Authority area.
The City Freedom can be obtained by residents after serving a period of "servitude", i.e.
apprenticeship (traditionally seven years), before admission as a Freeman.The annual ceremonial Beating of the Bounds by the River Medway takes place after the Admiralty Court, usually on the first Saturday of July.There were three medieval parishes: St Nicholas', St Margaret's and St Clement's.During the Roman conquest of Britain a decisive battle was fought at the Medway somewhere near Rochester.The first bridge was subsequently constructed early in the Roman period.The City of Rochester's ancient status was unique, as it had no formal council or Charter Trustees nor a Mayor, instead having the office of Admiral of the River Medway, whose incumbent acted as de facto civic leader.