Historical geography of the city Devin and its place in the relations of Iran and Byzantine in the Sassanid era

To determine the historical geography of cities over a period of historical political, military, economic and religious have a special, makes the analysis more accurate and cause and effect of events take place during that period. Among these cities should be in the border town of Devin pointed out that the geographical location of special place, although the city's age to the third millennium BC, but its growth and development in the mid-fourth century can be traced. At the same time as replacing the former capital of Armenia, the Armenian artashat and after the extinction of the Parthian dynasty, was selected as a border settlement. In fact, this research seeks to geographical location of the city and the reasons for its importance in Iran and Byzantium's circle competition. To achieve this purpose, the methods of historical research (descriptive) and based on the evidence and the views of researchers, used. The findings of this study suggest the importance of politico-military, economic, commercial and religious city, due to its geographical location. As the takeover of the city by Iran and Byzantium as Mesopotamia and dominate the coastal areas of the Black Sea region was considered. And from these areas could easily threaten each other's administrative center. In terms of religious as well as economic and trade exchanges between the two countries was one of the centers where it took place .And in certain cases where religious councils were formed.