Rumkale

Rumkale (lit. 'Roman Castle'; Հռոմկլա ), also known as Urumgala, is a fortress on the Euphrates, located in the province of Gaziantep and 50 km west of Şanlıurfa.

Ancient History
Its strategic location was already known to the Assyrians and it is possible that it was fortified by the Romans, no remains of periods earlier than 1000 CE have been identified at the side. It is said that John, an apostle of Jesus, lived in Rumkale during Roman times. It was then part of the Byzantine Empire.

Medieval History
In the late 11th century, the castle now known as Hromgla was part of the Armenian principalities of first Philaretos Brachamios and then Kogh Vasil. It was for some time under Latin rule with an Armenian bishop present before Gregory III purchased it from Beatrice of Turbessel in 1148 or 1150 to obtain a safe settlement for the Armenian Catholicosate. Gregory's brother Nerses IV was elected as Armenian Catholicos here in 1166 and it seems that at this time a very considerable settlement existed there during his time that also housed representatives of the Syriac Orthodox and the Catholic Church.

The castle became then part of the Armenian Kingdom of Cilicia. In the 1170 and 1172, theological conferences exploring a union of churches were held at Hromgla between the Armenian Church and the Byzantine Church with the Syrian Orthox (Jacobite) Church sending observers. In 1179, a synod of 33 Armenian bishops took place in Hromgla came up with a compromise and sent a profession of faith to Byzantine Emperor Manuel I Komnenos, but he died in September 1180 before it reached him. From 1203 to 1293, it served as the residence of the Catholicos of the Armenian Church. The site became an important center for manuscript production, reaching its artistic peak under the Catholicos Constantine I who employed Toros Roslin, whose stylistic and iconographic innovations had profound influence on subsequent generations of Armenian art.

In 1292, it was captured by the Mamluks of Egypt following a protracted siege who then named it Qal'at al-Muslimin.

Access
The fortress, now situated across a peninsula created by the reservoir of Birecik Dam and within the administrative boundaries of Gaziantep's Nizip district, is currently accessible by boat either from the neighboring site of Zeugma or from the town of Halfeti. As of March 2017, it was not possible to land at the site; extensive (re)building is underway inside the fortress and on the external walls.