Istria

From Latin Histria, from Ancient Greek Ἱστρία (Histría), named after Ἵστρων (Hístrōn) (ἔθνος (éthnos)), the ethnicon of the Illyrian/Venetic tribe of the Histri who inhabited the region.

The name could itself be related to Hister, a Roman name for the Danube, from Ancient Greek Ἰστρίη (Istríē), the Dacian-Thracian name for the river god Danubius, a name meaning "swift," and ultimately from Proto-Indo-European *dʰenh₂- (“to flow”). Also see Histria.