Municipium
A municipium was a Roman city of the second highest rank.

A municipium was the second-highest rank of Roman city, following after colonia. Each colonia was governed by an ordo (council), under the control of four annually elected magistrates (two duoveri and two aediles).

Unlike colonia, inhabitants of municipia were not automatically Roman citizens, but magistrates and their families did become citizens at the end of their time in office.

Only one municipium is known to have been established in Roman Britain, at Verulamium (St. Albans).

The levels of Roman cities - in descending order - are as follows: Colonia Municipium Civitas capitals

Related:
Colonia
Civitas

History
Prehistory - Roman Britain - Dark Ages - Medieval Britain - The Tudor Era - The Stuarts - Georgian Britain - The Victorian Age