Nymphius: river in ancient Armenia, modern Batman (in Turkey).
The ancient river Nymphius, today known as Batman, is not particularly famous. It flows from the Antitaurus Mountains in the north down to the Upper Tigris, in which it empties itself, about halfway between the city of Amida and the fort at Cepha.
The river plain, now dominated by nodding donkeys, were very fertile and the small state of Šupria was a natural target for the Assyrians, who conquered it in 672 BCE. Later, the plain was one of the northernmost possessions of the Babylonian Empire, and later, it belonged to the Achaemenids; after the fall of their empire, it was probably part of Armenia.
Among the cities on the plain of the Nymphius was Tigranocerta, founded by the Armenian king Tigranes II, and the site of his defeat against the Roman commander Lucullus in 69 BCE. It is almost certainly identical to the town that was later known as Martyropolis, modern Silvan.
The river Nymphius was part of the boundary drawn by the Roman emperor Jovian and the Sasanian king Shapur II in 363 CE. The governor (dux) of this frontier section, called Sophanene, resided in Martyropolis. According to Procopius, the emperor Justinian (r.527-565) was the first to improve this section of the border.note[Procopius, Buildings 3.2.]