university ofTehran Historical Sciences Studies 2251-9254 10 1 2018 08 23 An Analysis of the Great Crisis in the Sassanian Empire in the Late Third Century AD (Homeland Chaos; Failure Against the Romans) An Analysis of the Great Crisis in the Sassanian Empire in the Late Third Century AD (Homeland Chaos; Failure Against the Romans) 19 37 68587 10.22059/jhss.2018.247377.472913 FA Parviz Hossein Talaee Shahid Bahonar University of Kerman Alireza Soleymanzadeh University of Sistan and Baluchestan, iran Journal Article 2017 12 15 Since its inception in 224 AD, the Sassanid government adopted a policy of aggressive against its western neighbor; so that at the time of the first kings of this state (especially Shapur I), the Romans suffered several defeats against it. Although during the reign of his successors, up to the time of Shapur II this policy lost its strength the Sassanid Empire faced crises that affected its foreign policy. Considering the importance of the issue, this study is to find the reasons for the crisis in the late third century of the Sassanid government and their passivity in foreign policy. The findings show that after the Shapur I, the Sassanid government faced a succession crisis and its consequences (internal turmoil and fratricide). In fact, during this time when weak kings came to the power, the aristocrats and the Zoroastrian priests were the true rulers of Iran; So, the conflicts at the highest levels of the society and the competitive approach to power were among the factors contributing to the tensions within the structure of the Sasanian political system at the end of the third century. Such issues not only weakened the government's ability to resolve domestic crises within the power sector, but also exacerbated external crises and ultimately caused undeniable destructive effects on the structure of government and society. Under such circumstances, some Roman Caesars, having been aware of the devastation of the Sassanid government, arranged some attacks against the country and succeeded, to some extent. Since its inception in 224 AD, the Sassanid government adopted a policy of aggressive against its western neighbor; so that at the time of the first kings of this state (especially Shapur I), the Romans suffered several defeats against it. Although during the reign of his successors, up to the time of Shapur II this policy lost its strength the Sassanid Empire faced crises that affected its foreign policy. Considering the importance of the issue, this study is to find the reasons for the crisis in the late third century of the Sassanid government and their passivity in foreign policy. The findings show that after the Shapur I, the Sassanid government faced a succession crisis and its consequences (internal turmoil and fratricide). In fact, during this time when weak kings came to the power, the aristocrats and the Zoroastrian priests were the true rulers of Iran; So, the conflicts at the highest levels of the society and the competitive approach to power were among the factors contributing to the tensions within the structure of the Sasanian political system at the end of the third century. Such issues not only weakened the government's ability to resolve domestic crises within the power sector, but also exacerbated external crises and ultimately caused undeniable destructive effects on the structure of government and society. Under such circumstances, some Roman Caesars, having been aware of the devastation of the Sassanid government, arranged some attacks against the country and succeeded, to some extent. https://jhss.ut.ac.ir/article_68587_ce644949efede8fd217d5a2423fead8e.pdf