Romania is the European country whose city of Constanța contains the largest port on the Black Sea.
The Port of Constanța occupies Romania's western Black Sea coast and connects maritime shipping with the Danube through the Danube–Black Sea Canal. Its location gives cargo access to Central and Eastern Europe by sea, river, rail and road. The port complex also includes the satellite ports of Midia and Mangalia.
Constanța itself has ancient roots. The Greek colony of Tomis was founded in the sixth century BC, and the Romans later developed the settlement; the modern name honours Emperor Constantine I. Major modernization of the port began in 1896 under King Carol I, and the first modern port facilities opened in 1909.
A useful distinction is that Constanța is both a maritime and river-linked port. It is not a port on the Danube proper: the canal provides the connection. The city is also Romania's principal Black Sea commercial and passenger centre.