Rhabdion
Rhabdion was an early Byzantine fortress, located to the northeast of Nisibis on the border with the Sasanian Empire. It is now identified with Hatem Tai castle in southeastern Turkey.
It was probably built, along with Amida and Cepha, by Emperor Constantius II. after the loss of the trans-Tigris areas and some border forts to the Sasanians in 363, Rhabdion became the easternmost Roman frontier outpost, perhaps even de facto exclave in Persian territory, since the only road to it appears to have been from the south, passing across the plain by the Persian-controlled city of Nisibis.
The Hatem Tai castle was visited in the early 1860s by John George Taylor, then British consul in Diyarbakir, who sketched its outline in his Travels in Kurdistan. At the time, the Hatem Tai castle was identified with another ancient fortress known from the history of the Roman–Persian Wars of Late Antiquity, Sisauranon.
The castle may have given its name to the region of Tur Abdin.
