Histria or Istros (referring to Thracian river god, Danube – Ἰστρίη, ), was a Greek colony or polis near the mouths of the Danube, on the western coast of the Black Sea. It was the first urban settlement on today’s Romanian territory when founded by Milesian settlers in the 7th century BC. It was under Roman rule from the 1st to 3rd centuries AD. Invasions during the 7th century AD rendered it indefensible, and the city was abandoned. In antiquity, it also bore the names Istropolis, Istriopolis, and Histriopolis.
Established by Milesian settlers in order to facilitate trade with the native Getae, it is considered the oldest urban settlement on Romanian territory. Scymnus of Chios (ca 110 BC), dated its founding to 630 BC, while Eusebius of Caesarea set it during the time of the 33rd Olympic Games (657 – 656 BC). The earliest documented currency on today’s Romanian territory was an 8-gram silver drachma, issued by the city around 480 BC.
Archaeological evidence seems to confirm that all trade with the interior followed the foundation of Histria. Traders reached the interior via Histria and the Danube valley, demonstrated by finds of Attic black-figure pottery, coins, ornamental objects, an Ionian lebes and many fragments of amphoras. Amphoras have been found in great quantity at Histria, some imported but some local. Local pottery was produced following the establishment of the colony and certainly before the mid-6th century. During the archaic and classical periods, when Histria flourished, it was situated near fertile arable land. It served as a port of trade soon after its establishment, with fishing and agriculture as additional sources of income. By 100 AD, however, fishing had become the main source of Istrian revenue.
Around 30 AD, Histria came under Roman domination. During the Roman period from the 1st to 3rd centuries AD, temples were built for the Roman gods, besides a public bath and houses for the wealthy. Altogether, it was in continuous existence for some 14 centuries, starting with the Greek period up to the Roman-Byzantine period. The Halmyris bay where was the city founded was closed by sand deposits and access to the Black Sea gradually was cut. Trade continued until the 6th century AD. The invasion of the Avars and the Slavs in the 7th century AD almost entirely destroyed the fortress, and the Istrians dispersed; the name and the city disappeared.