Iran’s last century could be divided into two distinct periods: The Pahlavi’s Era and the Era of the Islamic Republic. I. In each of these epics, we have 2 different leaders whose visions and aspirations not only defined each leader’s mission but also the course that Iran was to pursue during their reigns. In this paper, I will argue that the four leaders who ruled Iran during the past 100 years are the key to understanding Iran’s visions and ambitions as well as their grand projects and designs for Iran. I will also demonstrate how these visions or aspirations could explain each leader’s domestic and international crucial policies. Reza Shah’s Modernization project, Mohammad Reza Shah’s ambitious project of taking Iran to the gates of a great civilization, Ayatollah Khomeini’s task of establishing a Shia Theocracy, and Ayatollah Khamenei grand project of congealing Islamic governance and civilizational claims capture Iran’s visions, ambitions, and her place in the world from 1921 to 2021. I will focus on the historical context under which each of these grand projects was created and eventually adopted by these leaders. I will also provide an assessment of their achievements and legacies as well as their shortcomings.