The Batman River is a major tributary of the Tigris, joining it near the source of Tigris called Dicle River in southeast Turkey. It originates in the Anti-Taurus Mountains and flows approximately from north to south, passing near the city of Batman and forming a natural border between the Batman Province and Diyarbakır Province. The historic Malabadi Bridge crosses the river near the town of Silvan. The region along the Batman River is known for its oil fields. The Batman Dam was built in 1999 in the upstream, together with the associated reservoir and hydroelectric power plant. The river is widest at about right after exiting the dam, but then narrows to about and forms numerous splits along its way to the Tigris. Its riverbed is irregular in many places, promoting flooding. A tributary of Batman, the Iluh River, originates in the Raman Mountain on the south of the Batman city and flows north-west through the city into the Batman River. Despite being a small river, absent on most maps, Iluh plays an important role for the province because its spring floods affect the provincial capital. The floods of Iluh and Batman rivers occur between March and May and sometimes in October or November. Major floods occurred in 1969, 1972, 1991, 1995 and 2006. In Antiquity, the Batman River was known as Kalat. This name meant "bride" to the Syriac people who populated the area; it was thus translated into Greek as Nymphios and Nymphaios. Among Arabs it was known as Satidama, meaning "the bloody" reflecting the battles fought near it. The river served as a natural border between the Byzantine Empire and Sassanid Persia and saw major battles in 583 and 591 AD. The main citadel on the river was Martyropolis, modern Silvan. In international literature, the name Batman came into use since the 19th century, whereas in the 18th century and before it was mostly referred to as Nymphius, among other names. The origin of the name "Batman" is unclear: it might be a shortening of the name of the tall Bati Raman mountain located nearby or refer to the unit of weight used in the Ottoman Empire.
