Colony

The city of Philippi was a Roman colony (Acts 16:12), i.e., a
military settlement of Roman soldiers and citizens, planted
there to keep in subjection a newly-conquered district. A colony
was Rome in miniature, under Roman municipal law, but governed
by military officers (praetors and lictors), not by proconsuls.
It had an independent internal government, the jus Italicum;
i.e., the privileges of Italian citizens.