This chapter focuses on the changing role and orientation of the clergy, above all their use of and commitment to several key features of modernization, especially to the reconstruction of society through political processes. The Reza Shah's government secularized and codified laws, adopted European-style legal codes, and established a system of secular courts that greatly reduced the judicial functions of the ulama. During the reign of the first Qajar shahs, the vaqf properties increased and the ulama regained the control over the administration of the auqaf. In 1971, Ayatollah Ruhullah Khomeini's lectures for theology students were published in a very important book named Velayate faqih, hukumat-e eslami which was to play a crucial role in the Islamic Revolution of Iran. Khomeini's religious work and the theory of velayat-e faqih provided an intellectual framework for an Islamic government as the only legitimate government in Muslim communities.