Zerzevan Castle water system in the light of 2014-2015 excavations

Northern Mesopotamia hosted many civilizations along with the first traces of the settled life. In addition to having water resources such as the Tigris and the Euphrates, which is one of the greatest factors in people's acquisition of new settlements, this geographical area, which is located on important trade routes, is given much importance by Rome both during the republic and the empire. The territories, as part of the Eastern Mediterranean politics blended with Rome's tolerance policy, have managed to attract attention throughout the history of the empire. In this sense, the Roman Empire had been in great struggles with Parth and Sassanids throughout the Tigris and Euphrates basin, and the victories it won have eventually transformed the cities it acquired into a part of the Syrian Land. As a consequence of the increasing threats of the growing empire, the progression policy brought with it the need for new defense areas. For this reason, the garrisons such as Zerzevan Castle were built not only on places close to water resources but also on the high hills which were easy to defend. The "vaulted cisterns, water canal and underground cisterns" unearthed by the excavation works carried out in the Zerzevan Castle in 2014-2015 were examined and the closest sources in the city to which the water could be transferred were evaluated and the way of storing water and the construction techniques used for this purpose were determined. In this research, taking into consideration the annual average rainfall of Diyarbakir, the total water transport capacity of the reservoirs was evaluated and the number of people in the village was determined as minimum 1000-1500. In this sense,the basic canon which was supported by the data that gained in excavations stated as the most important needs in castle, in degree that can manage long-needed situations, by having the most important arrangement toward the water provision, and a garrison that have a critical settlement that has been witnessed the most important struggles in Zerzevan Castle's Roman-Sassanid struggle.