How did the north-south divide develop in 19th-century Tehran?

The north-south divide in 19th-century Tehran emerged as a consequence of major modernization programs that transformed the capital during the latter part of the century. As the city expanded significantly in size—adding new walls, gates, institutions, and neighborhoods—this new urban structure began to separate the population along socioeconomic and cultural lines, distinguishing the rich from the poor and the modern from the traditional.1

This divide was further reinforced by the city's geography and climate. Historically, the more affluent residents favored the northern foothills for their summer residences, where the climate was cooler and trees were more plentiful. In contrast, the southern areas were closer to the desert, resulting in hotter, dustier conditions. As the 19th century progressed, these physical and environmental differences helped solidify a social geography where the north became associated with greater physical and social advantages, while the south became increasingly characterized by poverty and economic decline. By the end of the century, these structural and social disparities left Tehran poised for a period of significant social conflict and revolutionary turmoil.213