The Formation and Development of Birjand City According to Historical Documents and Archaeological Evidences

No archaeological excavations have yet been carried out in the old district of the city of Birjand, the capital of South Khorasan province, albeit of its valuable historic district. Therefore, its formation and development throughout history are not clearly known. Studying historical sources and texts, which are limited, and using the historical evidence and monuments and the city borders, the formation and growth of Birjand could be understood. The desert climate of a large part of South Khorasan has led to environmental conditions not present everywhere in this region to form living places. Birjand is geographically formed in an environment with fertile soil, available water, and favorable weather in hot and cold seasons than neighboring areas. Also, its linking role and location in the connecting route of Khorasan and Sistan throughout history and the transfer of centrality from Qaen to Birjand during the Safavid period to the Qajar always plays a significant role in the growth and development of the city. In the middle of the Qajar period, the city's importance caused the British and Russian countries to establish consulates in Birjand. In this period, we witnessed the formation of new neighborhoods as well as markets in the city. This study aims to study the formation and development of Birjand city based on geographical conditions, historical texts, and archaeological data. The findings were collected through library and field studies with a historical and cultural approach and descriptive and analytical methods. Finally, this article seeks to answer these questions: (i) what factors have influenced the growth and development of Birjand over time? (ii) according to the architectural evidence in the old district of Birjand, where are the areas of formation of the city, and in what period is it considered the center of Qohestan?