During the Qajar period the two shrine cities ('Atabādt-e ‘āliydāt, lit. Sublime Thresholds) of Najaf and Karbala, south of Baghdad, served as the leading centers of learning for the Shi'i world. As such they were also at the center of patronage networks that were essential for the consolidation of the religious leadership of all Shi'i communities. Yet, whereas various scholars have examined doctrinal and political developments in the religious establishment in Iran, none have dealt specifically with the ‘Atabat community of learning during the 19th century. The purpose of this study is to examine patterns of continuity and dynamics of change in the composition of the ulama community of the ‘Atabat, based on ethnic, professional, and geographical factors. Such research could shed light on the structure and characteristics of the entire ulama community in Iran and specifically in Ottoman Iraq.