Chapter 3 provides a complementary discussion of the umma in Shi‘i thought and practice. While religious authority is central, as with the Sunni conception, the Shi‘i conceptualisation of the Imams elevates genealogical descent and theological erudition to essential ingredients of leadership. It follows that their absence from this world created a dilemma with religious and political significance: who would guide the community until the return of the redeeming Imam Mahdi (Guided One)? From the medieval centuries to the modern period, a rough consensus emerged that the clerical class would fill the void of religious guidance. The minority view that they should also have a political role found its full articulation, in the last quarter of the twentieth century, in Ayatullah Ruhollah Khomeini’s theory of clerical rule and its institutionalisation in the Islamic Republic. The chapter shows that the Khomeinist-revolutionary Iranian appeal to lead the universal umma has, however, been undermined by an assertive sectarian interpretation and geopolitical rivalries.