Researchers investigating the ancient mountain fortress of Rabana-Merquly in Iraqi Kurdistan have been shedding light on the Parthian-era centre, potentially identifying it as the royal city of Natounia, a place only known from seven coins.

High in the Zagros Mountains, the large complex contains two main settlements (Rabana and Merquly) inside nearly 4km-long fortifications. It was located close to the eastern border of Adiabene, a vassal kingdom under the sway of the Parthian Empire, which controlled parts of Iran and Mesopotamia between the 3rd century BC and the 3rd century AD. As part of an international project looking at the ancient Iranian highlands, archaeologists have mapped the site using drones and carried out excavations between 2009 and 2022.
So far, rectangular buildings – possibly barracks – have been identified, offering important evidence of Partho-Sasanian military architecture and planning, as Michael Brown, Kamal Rasheed Raheem, and Hashim Hama Abdullah note in their recently published study in Antiquity (doi.org/10.15184/aqy.2022.74). The scale of the site makes it likely that there was official state involvement in building and running Rabana-Merquly and its military structures, which, the authors write, challenges ‘the prevailing notion of an inherently weak Parthian state.’
Brown, of Heidelberg University, said, ‘There does appear to have been a particular focus on fortification building in the Zagros region during the Parthian and Sasanian periods. This was to a large extent due to geopolitical factors and in particular controlling strategic overland communications through the highlands between the Iranian plateau and the Mesopotamian plain.’ Based on the architectural association between Rabana-Merquly’s rock reliefs, fortifications, and settlements, and some specific types of pottery, the team have tentatively dated the site’s main building phase to the 1st century BC.

As well as the date, the rock reliefs also provide a clue as to the ancient identity of Rabana-Merquly. Two rock reliefs stand at the fortress’s gated entrances, each depicting a ruler in Parthian-style dress. A similar likeness of a king of Adiabene, named ʾtlw/Attalos, comes from the Parthian city of Hatra, 230km away, and its inscription mentions his ancestor and founder of the Adiabene dynasty, Ntwn ͗šr/Natounissar. A place-name combining this king’s name and the Parthian word for a fortification or moat, ‘Natounissarokerta’, appears on a handful of bronze coins. Coins give us the only references to this city, its other name ‘Natounia’, and its description ‘on the Kapros’ (as the Lower Zab River was known in antiquity). Rababa-Merquly lies within the Lower Zab watershed, so it is possible that this could be the ‘fortification of Natounissar’ ‘on the Kapros’ known from coins. It may be the city’s founder, Natounissar or a descendant, that we see in the rock reliefs.
In addition to military structures, excavations in 2017 found a stone structure with a staircase cut into the rock and an altar in a niche nearby. Located at the point of an occasional waterfall, this complex at Rabana could be a sanctuary, tentatively associated with the Zoroastrian water goddess Anahita. The site, suggests Brown, ‘may have also been a place of pilgrimage, in addition to acting as a refugium for surrounding communities.’
The different roles of Rabana-Marquly and other fortified centres with a mix of buildings, like Qalʾeh-i Yazdigird in Iran’s Kermanshah province (which also has a sanctuary), are something the team will work to try to understand as the research project, funded by the German Research Foundation, continues.