In the history of the Roman empire, a vicus (pl. vici) was an ad hoc provincial civilian settlement that sprang up close to and because of a nearby official Roman site, usually a military garrison or state-owned mining operation. The name vicus was also used for the subdivisions of a town, the smallest administrative units.

Ad hoc settlements

Vici differed from the planned civilian towns (civitates), laid out as official, local economic and administrative centres, the coloniæ which were settlements of retired troops, or the formal political entities created from existing settlements, the municipia.

Unplanned, and originally lacking any public administrative buildings, vici had no specific legal status (unlike other settlements) and developed in order to profit from Roman troops with little to distract them otherwise when off duty. As with most garrison towns, they provided entertainment and supplies for the troops but many also developed significant industries, especially metal and glass working.

Initially quite ephemeral, many vici were transitory sites that followed a mobile unit; once a permanent garrison was established they grew into larger townships. Often the number of official civitates and coloniæ were not enough to settle everyone who wished to live in a town and so vici also attracted a wider range of residents, with some becoming chartered towns where no other existed nearby. Some, such as that at Vercovicium (Housesteads) outgrew their forts altogether, especially in the third century once soldiers were permitted to marry.

Early vici had no civilian administration and were under the direct control of the Roman military commander. Those that attracted significant numbers of Roman citizens were later permitted to form local councils and some, such as the vicus at Eboracum (York), grew into regional centres and even provincial capitals.

Subdivisions of Rome

Vicus was the Latin name for the subdivisions into which the 4 regiones (regions, divided by tribes) of the city of Republican Rome were divided. Later, Augustus, as part of his major reforms, would change this system, into 14 regiones, divided into vici. A vicus consisted of one major street and several smaller streets, their total number was 424 and each vicus elected four local magistrates (vicomagistri) who commanded a sort of local police chosen from among the people of the vicus by lot. Occasionally the officers of the vicomagistri would feature in certain celebrations (primarily the Compitalia) in which they were accompanied by two lictors.