The assassination of Ayatollah Ali Khamenei, who ruled Iran for nearly four decades, initiates one of the most uncertain transitions in the history of the Islamic Republic, a process deeply influenced by the security establishment.
The supreme leader was killed in Israeli-US military strikes on Iran on Saturday. He had ruled since 1989, when he was chosen to succeed the Islamic Republic's founder, Ayatollah Ruhollah Khomeini.
Mr Khamenei did not publicly name a successor and Iran's Assembly of Experts had reportedly been examining potential candidates in secrecy without making any official announcement.
Here is how Iran's succession process works, who holds power in the interim and who the leading candidates to replace Khamenei are:
Who governs Iran now?
A Provisional Leadership Council (PLC) has stepped in and will rule until the Assembly of Experts appoints a permanent successor.
This council has a specific, constitutionally mandated composition: the sitting president, head of the judiciary and one cleric from the Guardian Council, chosen by the Expediency Discernment Council. At present, that means the PLC includes reformist President Masoud Pezeshkian and hardline judiciary chief Gholamhossein Mohseni Ejei, an unusual pairing.
The armed forces, including the Islamic Revolutionary Guard Corps (IRGC), and the judiciary continue to operate through their existing chains of command.
How is new supreme leader chosen?
The supreme leader is selected by the Assembly of Experts, an 88-member body of senior clerics. The assembly is popularly elected every eight years, but all candidates must first be vetted and approved by the Guardian Council, Iran's constitutional enforcer, which routinely disqualifies candidates it considers insufficiently loyal.
The assembly's current session was elected in 2024 and is chaired by Ayatollah Mohammad Ali Movahedi Kermani. Under the constitution, it must convene and select a new leader as soon as possible.
The supreme leader must be a male Islamic cleric, with political competence, moral authority and loyalty to the Islamic Republic. The constitution no longer requires the leader to be a Grand Ayatollah of the highest religious rank. That requirement was removed in the 1989 constitutional referendum, which is precisely what allowed Ali Khamenei, who was not at that level, to be selected and then elevated in rank after the fact.
The assembly may also opt to appoint a leadership council of a number of clerics rather than an individual. That option has never been used but has been discussed in Iranian circles in recent years.
What is the role of the IRGC?
While the succession process is formally controlled by clerics, the Islamic Revolutionary Guard Corps exercises decisive influence.
Over the decades, it has grown into Iran's most powerful institution, overseeing military operations, intelligence and vast economic interests. Any successor will almost certainly require the IRGC's backing to govern effectively, regardless of formal religious credentials.
The timing of Mr Khamenei's death, during a war, makes the IRGC's stabilising role even more important.
Who are the leading candidates?
No candidate has been officially named and deliberations are strictly confidential. Reported assessments of potential successors are based on analysis and rare leaks.
Mojtaba Khamenei
Mojtaba Khamenei, 56, is the second son of the late supreme leader and has long been considered a potential successor due to his close ties to the IRGC and the Basij paramilitary.
He has never held government office and lacks the senior religious credentials typically expected of the role. Reports from mid-2025 suggested the Assembly of Experts had excluded him from a confidential shortlist, though other sources indicate he may still be in contention.
Sadegh Larijani
A former judiciary chief with strong religious credentials and long institutional experience.
He is closely aligned with the regime's ideological core. His clerical standing could give him legitimacy with religious institutions where Mojtaba Khamenei falls short.
Mohsen Araki
A senior cleric and close aide to the late supreme leader, Mr Araki has been cited by several sources in Iranian outlets as one of a small number who have appeared on confidential candidate lists maintained by the Assembly of Experts.
Hassan Khomeini
The grandson of the Islamic Republic's founder bears considerable symbolic and religious legitimacy. However, he is widely considered an outsider to the regime's power structures. He was barred from running for the Assembly of Experts in 2016 and is seen as less hardline than most of his peers.
What happens next?
The Assembly of Experts must convene as soon as possible. If a consensus candidate exists, a successor could be named relatively quickly.
If factions disagree, and the competing interests of the clerical establishment, the IRGC and hardline versus pragmatic factions prolong the disagreement, the process could involve extended and opaque behind-the-scenes negotiations.
However, the assembly faces an extraordinary challenge in convening and deliberating while the country is under attack, and when gathering in one place may itself be a security risk. The choice of successor will determine not only who governs Iran, but how the Islamic Republic attempts to survive this most significant of crises.
