Any analysis of the behaviour of the pro‐Iranian Hizbollah organisation in Lebanon requires both an understanding of the movement itself, in terms of its decision‐making apparatus and internal clerical factionalism, and the mechanisms of its institutionalised relationship with Iran and, to a lesser extent, Syria through military and civilian channels at work within Lebanon. This article argues that Hizbollah's behaviour is principally governed by the depth and allegiance of closely forged relationships between individual Hizbollah leaders and Iranian clergy as well as the adaptability of a particular Hizbollah leader to suit the movement's activity to specific requirements within Lebanon and in the region. As such, clerical factionalism within Hizbollah can be monitored by the ascendancy or demotion of clergymen over the leadership and is also a guide to the direction of the movement in Lebanon as well as to the affiliation and loyalty of Hizbollah's leadership with clerical factions and institutions in Iran.