This work contains a number of speeches, articles, books, and question-and-answer sessions of the erudite professor, Haḍrat Ayatullah Muhammad Taqi Misbah Yazdi (may his sublime presence endure), which have been compiled, edited and published by the author on the subject of Wilayat al-Faqih. We believe that in the current status of our society, wilayat al-faqih constitutes the central pillar of Islam, and its safety contributes to the splendor of Islam and Islamic laws and values in the society. As such, we have decided to elucidate this theory, support it academically and logically, and enlighten the general public, particularly the young generation of our country who probably know very little about this theory and its ramifications, and thus discharge a small part of our religious duty. Likewise, we have tried to deal with all the aspects of this theory to address the subjects which we find significant and controversial. However, things like the brevity of content and the readers’ patience and the time that they have been taken into account as far as possible.