A colonia was a settlement of citizens (with the addition of a greater or lesser proportion of non-citizens) for the military and political securing of Roman rule, later for providing for veterans and occasionally the Roman proletariat, almost always in a conquered city, the citizens of which would also be involved in the colony in some way (cf. the definition in Serv. Aen. 1,12).
Galsterer, Hartmut (Bonn),
Brill’s New Pauly, Antiquity volumes edited by: Hubert Cancik and , Helmuth Schneider, English Edition by: Christine F. Salazar, Classical Tradition volumes edited by: Manfred Landfester, English Edition by: Francis G. Gentry.
Consulted online on 23 January 2019 <http://dx.doi.org/10.1163/1574-9347_bnp_e303060>