This application of the words "metropolis" and "metropolitan" came from Ancient Greek "metropolis" (from μήτηρ mētēr "mother" and πόλις pólis "city, town"), which was the name for a city-state that created colonies across the Mediterranean (e.g. Marseille was a colony of the city-state of Phocaea; therefore Phocaea was the "metropolis" of Marseille).
Denne brug af ordet "metropolis" og "metropolitan" kom fra Antikkens græske "metropolis" (fra μήτηρ mētēr "mor" og πόλις pólis "by") som var navnet på et bystat som havde kolonier langs Middelhavet (eks Marseille var en koloni tilhørende bystaten Fokaia, dermed var Fokaia "metropolis" for Marseille).