The Analysis of Effective Factors in Territorial Relations between Sasanian and Byzantine Empire in the Fifth Century

From the foundation of Sasanian Empire in 224A.D, the hostile policies were employed toward Rome Empire by Ardishir Babakan, who was the first sovereign of this dynasty in Iran. Although the backgrounds of such policies could be found in Arsacid era, Ardishir Babakan made an ideological existence of this hostile relations in order to restore the territories of his ancestors, which had been taken by Rome Empire. This issue eliminated the possibility of agreement between two empires. Consequently, the relations between these empires were based on ongoing wars, however, the fifth century can be regarded as a peaceful period for such relations. The present study endeavors to investigate effective factors in foreign policy between Rome Empire and Sasanian Empire in the 5th century based on library studies with analytical - descriptive approach. The outcome of this research reveals that the peaceful period in the relations of these empires was under the influence of some reasons such as instability of Sasanian Empire, the hostility in the eastern territories and the invasion of nomad tribes in the northern territories of Rome Empire.