Analysis of the Parameters Affecting Frontier Policies of Ardashir towards the Roman Empire

The Sassanid dynasty established in 224 CE, when Ardashir conquered Ardavan V (Parthian King) in Hormozgan battle. After consolidating and strengthening the central government, the founder of this dynasty decided to expand frontiers of his territory from north - west, west and south. In order to achieve this goal, he had to be grappled with the Roman Empire that had begun his constant conflict with Iran from the Parthian era. The purpose of this research is to analyze the parameters affecting frontier policies of Ardashir towards the Roman Empire and how much he has managed his goals. Method of this study is descriptive and analytical which is based on library Studies. The result of this article is that Ardashir I, who considered himself as the heir of Achaemenid Empire, decided to restore its frontiers. To achieve this goal, other important enterprises were necessary including: domination of Armenia, capturing strategic areas of Mesopotamia and especially the strategic town of Hetra and taking control of Persian Gulf trade and trade ways of Mesopotamia.