This paper is an attempt to examine, with narrative explanation technique, the notion of the "other" in the history of Iran's foreign relations from the perspective of Historical Sociology in International Relations. It covers the historical period following the founding of the Safavid state in 1502 A.D. through the first decade of the Islamic Republic (1989 A.D.). From the perspective of how the "other" is perceived, and based on theoretical and methodological considerations, Iran's foreign relations are divided into three periods; in the Safavid period, it is the internal events that affect the way the "other" is perceived. In the Qajar and Pahlavi eras, however, it is the external developments that shape the way the "other" is seen. In the Islamic Republic, it is both the internal and external events that affect this perception of the "other" in the country’s foreign relations. Based on the above- mentioned ideas, it is suggested that the perception of the "other" in Iran’s foreign relations go through the phases of emergence, transformation, and establishment within a framework of a chain of narratives regarding internal and external developments. In this process, one should also consider the role of human beings, and the main decision-making actors and their influence on the perception of the "other". It is suggested that during the Safavid period, it is the inter-religious conflicts vis-a-vis the Sunni Ottoman Empire that shape the perception of the "other". This perception was transformed during the Qajar and Pahlavi eras in confrontation with major colonial powers of the 19th century and continued during the Cold War era. Finally, it reached its peak and was institutionalized in the first decade of the Islamic Republic. To sum up, affected by the internal and the external events, the "other" evolves from the construction phase to the establishment phase in the history of Iran’s foreign relations.