As Mojtaba Khamenei assumes power in Iran, the clerical establishment is framing the death of his father, Ayatollah Ali Khamenei, as martyrdom for Islam and casting the new supreme leader as heir to the Islamic Republic’s legacy of resistance.
In a message congratulating Mojtaba on his appointment Sunday, Hassan Khomeini—the grandson of the Islamic Republic’s founding ayatollah—offered “condolences on the martyrdom of your beloved father, who was a model of jihad and martyrdom.”
The rhetoric appears aimed at rallying Iran’s religious base behind the new leader as the regime faces what its leaders portray as an existential struggle with its enemies. It draws on core Shiite themes of martyrdom and resistance, reinforcing the image of the younger Khamenei as the rightful successor to lead the Islamic Republic.
It helps elevate the younger Khamenei’s religious and political standing. He has close ties to the Islamic Revolutionary Guard Corps and the state’s security apparatus and isn’t widely regarded as a religious authority. His appointment also goes against a long-held notion in the Islamic Republic that hereditary rule is a sin practiced by un-Islamic monarchies.
Ayatollah Ali Khamenei was killed Feb. 28 during Israeli and American bombardments. The younger Khamenei’s mother, wife and a son were also killed in airstrikes during the war.
“Mojtaba will be helped by the fact that his father was killed by Netanyahu and Trump,” said Eskandar Sadeghi-Boroujerdi, an Iran expert at the University of St. Andrews in Scotland. “You can already see the mythology being built.”
The appointment of Khamenei to succeed his father also sends a message to President Trump that the regime won’t be cowed by the military campaign. Trump said in recent days that Khamenei was an unacceptable replacement and that he should approve Iran’s new supreme leader. Analysts say that stance may actually bolster Khamenei’s legitimacy.
Martyrdom is a central concept in Shiite Islam, harking back to the death of Imam Hussein, the Prophet Muhammad’s grandson, who was killed in the seventh century after refusing to pledge allegiance to a ruler who had inherited power. Hussein’s death in battle in Karbala, Iraq, alongside members of his family, has been invoked by Iran’s leaders since the 1979 revolution as a model for revolutionary struggle.
The late supreme leader was also killed alongside his family, at home, during the Muslim holy month of Ramadan. Iranian state media now refers to his son, who was injured in the bombardments, as the “Jaambaz” of Ramadan, a term used for war veterans wounded in battle.
“In many ways, he is now the embodiment of the Karbala story. That, on a very deep level, means something in Iranian society, even among those who aren’t especially pious,” said Narges Bajoghli, an associate professor at Johns Hopkins University’s School of Advanced International Studies and author of a book about regime power in Iran.
A council of senior Iranian clerics vowed to renew their pledge “with the pure blood of all martyrs from the beginning of Islam to the present day,” and to obey the new supreme leader “in the same way as the companions of Karbala pledged allegiance to their master.”
Iranian state media on Monday broadcast videos of crowds around the country pledging support for the new leader. In the northern city of Zanjan, thousands responded to chants memorializing the late Khamenei with the refrain: “We’re your followers, Seyyed Mojtaba,” using an honorific denoting a descendant of the Prophet Muhammad.
Mohammad Mokhber, a former Iranian vice president, called the new supreme leader “the complete mirror of our martyred leader, Imam Khamenei.”
“The medal of honor of being the son and husband of a martyr is also a sign of the depth of their faith and sacrifice,” he said.
Iran’s supreme leader serves as the country’s head of state, commander in chief of the armed forces and the highest authority in its political and religious system. The position is also regarded by many followers as the leading authority for the world’s roughly 200 million Shiite Muslims.
Khamenei had long been rumored as one of several potential successors to his father, in part because he spent decades operating in the shadows while cultivating close ties with the Revolutionary Guard and Iran’s intelligence services. He managed many affairs in his father’s powerful office, which still oversees military and clerical matters as well as a business empire worth billions of dollars.
His ascendance to power was long in the making, said Hamdi Malik, associate fellow at the Washington Institute think tank.
“Mojtaba Khamenei didn’t spend decades building a deep state inside Iran through the IRGC, its intelligence arm, the Quds Force, the Supreme Leader’s vast apparatus, and other key institutions only to surrender it all amicably to someone else,” he said.
The supreme leader must also be a mujtahid, a cleric qualified to issue religious rulings. While not a pre-eminent Islamic scholar, Khamenei has studied under various grand ayatollahs. In 2022, a news outlet associated with the seminary in the holy city of Qom referred to him as an “ayatollah” for the first time, suggesting he had reached the rank of mujtahid. But the process of determining religious credentials is decentralized, and Khamenei’s status is ambiguous.
“It is going to take a long time for them to use all the power of Islamic Republic to create this stature around him as a truly learned figure,” Sadeghi-Boroujerdi said.
The Iranian constitution rests on the concept of velayat-e faqih, or guardianship of the jurist, which gives the supreme leader his authority. Yet, the religious importance of the office has been watered down over time. Khamenei’s father also had limited religious credentials when he was appointed.
“Velayat-e faqih has changed form, from being about theological knowledge to being about political leadership, and especially against the U.S. and Israel,” Bajoghli said.
Write to Sune Engel Rasmussen at sune.rasmussen@wsj.com