A municipium was the second highest class of a Roman city, and was inferior in status to the colonia. The Roman Forum was the central area around which ancient Rome developed. ... A colonia was a Roman outpost, usually established by veterans of a Roman Legion, who received land as a part of their retirement from the Legions. ...

The essence of the municipium was that it was self governing.

The first municipium was Tusculum. The citizens of municipia (of the first order) held full Roman citizenship and rights (civitas optimo iure), which included the right to vote.

A second order of municipia were typically formerly important tribal centres. Unlike the first order of municipia, residents in these municipia were not full Roman citizens (but its magistrates could become so after retirement), but they partook of the duties of full citizens in terms of their liability to taxes and military service. Most significantly, they had no right to vote (this was the ultimate right in Rome, and a sure sign of full rights). A municipium was governed by a council of four annually elected officials, all under the thumb of Roman rule. Magistratus ordinarii (ordinary magistrates) and Magistratus extraordinarii (extraordinary magistrates) were two categories of officials who held political, military, and, in some cases, religious power in the Roman Republic. ...

The only known Municipium in Roman Britain was St Albans, then called Verulamium. Principal sites in Roman Britain Roman Britain refers to those parts of the island of Great Britain controlled by the Roman Empire between 43 and 410. ... St Albans (thus spelt, no apostrophe or dot) is the main urban area of the City and District of St Albans in southern Hertfordshire, England, around 22 miles (35. ... Remains of the city walls Verulamium was the third largest city in Roman Britain. ...