The death of any absolute ruler triggers a crisis of succession, but in the Islamic Republic of Iran, the process is both rigidly codified and deeply opaque. For nearly four decades, only one man has held the title of Supreme Leader – Ayatollah Ali Khamenei, who succeeded the founder of the revolution, Ayatollah Ruhollah Khomeini, in 1989. Now, with Khamenei’s death, the machinery of succession grinds into motion, exposing a constitutional process that has been tested exactly once in history.
The Constitution of the Islamic Republic, ratified in 1979 and revised in 1989, vests ultimate authority in the Rahbar, or Supreme Leader. This figure commands the armed forces, appoints the heads of the judiciary and state media, and has the final say on all matters of state. The Leader is chosen by the Assembly of Experts, an 88-member body of clerics elected by popular vote. On paper, this is a democratic selection. In practice, the Assembly is a handpicked organ of the clerical establishment, its candidates vetted by the Guardian Council, itself appointed by the Supreme Leader.
The Assembly’s mandate is straightforward: whenever the Leader dies, resigns, or becomes permanently incapacitated, the Assembly must convene within days to select a successor. The process begins with a closed-door session in Tehran, where the members debate candidates in secret. The Constitution requires the Assembly to choose a cleric who possesses “the necessary qualifications,” including jurisprudential expertise, political acumen, and “justness.” But the actual criteria have always been more political than theological.
When Khomeini died in June 1989, the Assembly moved with startling speed. Within hours of his death, the body elected Khamenei, then serving as president, as the new Supreme Leader. This was a controversial choice: Khamenei was only a mid-ranking cleric, a hojatoleslam, not an ayatollah. The Constitution at that time required the Leader to be a marja, a grand ayatollah – the highest rank in Shia Islam. To accommodate Khamenei, the regime convened a constitutional revision assembly that removed the marja requirement, effectively lowering the bar. Khamenei was later promoted to ayatollah by his supporters, but his religious credentials have always been questioned by more senior clerics.
That single succession established a precedent: the Assembly of Experts is not a deliberative body that weighs multiple candidates in public debate. It is a mechanism for ratifying a decision made by the inner circle of the security and clerical establishment. The real contest happens before the Assembly convenes, in the corridors of power in Qom and Tehran. The key players are the heads of the security services, the judiciary, the Expediency Council, and the most powerful clerics in the holy city of Qom.
The current Assembly of Experts, elected in 2016 and again in 2024, is dominated by conservatives and hardliners. Its composition reflects years of systematic vetting that has excluded reformists and moderates. The chairman, a veteran ayatollah in his eighties, has served as a close ally of Khamenei for decades. The Assembly’s members are overwhelmingly elderly; the average age is over 70. This demographic reality means that the succession debate is not purely ideological – it is also a question of generational transition.
The Constitution offers two paths for succession. The first is the direct election of a single successor by the Assembly. The second, rarely discussed, is the formation of a Leadership Council – a three- or five-member body that would collectively exercise the powers of the Supreme Leader. This council option was written into the 1989 revisions as a contingency, but it has never been used. Some analysts believe it could be revived if the establishment cannot agree on a single figure, or if the chosen candidate lacks the religious stature to rule alone.
Historically, the figures positioned as potential successors have fallen into three categories. First are the senior grand ayatollahs of Qom, men like the reclusive but revered teachers at the seminaries. These figures command religious authority but lack political experience and security connections. Second are the political clerics who have served in high state office – former presidents, heads of the judiciary, and members of the Expediency Council. These men have the political networks but often lack religious prestige. Third are the military-clerical figures from the Islamic Revolutionary Guard Corps, men who combine religious credentials with command experience. This last category has grown in prominence as the IRGC has expanded its economic and political power over the past two decades.
The succession process is further complicated by the factional rivalries within the conservative camp. The traditional bazaar clerics, the revolutionary hardliners, and the security establishment each have different priorities. The IRGC wants a Leader who will protect its economic empire and maintain a confrontational foreign policy. The traditional clerics want a Leader who will preserve the seminaries’ autonomy. The political class wants stability and continuity.
The human impact of this succession is profound. The Supreme Leader is not merely a political figure; he is the ultimate arbiter of the Islamic Republic’s identity. He can authorize or block nuclear negotiations, order military interventions, and sanction or protect dissidents. For the 85 million Iranians, the succession will determine whether the regime opens or closes, whether economic sanctions ease or tighten, and whether political repression intensifies or relaxes.
Geopolitically, the succession matters to every country in the Middle East. Iran’s network of proxies – Hezbollah in Lebanon, the Houthis in Yemen, Shia militias in Iraq, and the Assad regime in Syria – all look to Tehran for direction. A weak or contested succession could embolden Iran’s rivals, Israel and Saudi Arabia, while a seamless transition would signal continuity.
The lesson of 1989 is that the Islamic Republic prioritizes stability over religious legitimacy. The regime changed the Constitution to install Khamenei, and it can change the rules again. The Assembly of Experts will meet in private, debate in whispers, and emerge with a name. That name will hold absolute power over a nation of 85 million, for life. The only question is whether the system that produced him can survive him.
