Iran's supreme leader, Ayatollah Ali Khamenei, was killed in Israeli attacks, with U.S. support, on Saturday. He was 86 years old.

President Trump announced the Iranian leader's death on social media, saying Khamenei could not avoid U.S. intelligence and surveillance. A source briefed on the U.S.-Israeli attacks on Iran told NPR earlier Saturday that an Israeli airstrike killed Khamenei.

During his 36-year rule, Khamenei was unwavering in his steadfast antipathy to the U.S. and Israel and to any efforts to reform and bring Iran into the 21st century.

Khamenei was born in July 1939 into a religious family in the Shia Muslim holy city of Mashhad in northeastern Iran and attended theological school. An outspoken opponent of the U.S.-backed Shah Mohammad Reza Pahlavi, Khamenei was arrested several times.

He was surrounded by other Iranian activists, including Ayatollah Ruhollah Khomeini, who became Iran's first supreme leader following the country's Islamic Revolution in the late 1970s.

Khamenei survived an assassination attempt in 1981 that cost him the use of his right arm. He served as Iran's president before succeeding Khomeini as supreme leader in 1989.

Alex Vatanka, a senior fellow at the Middle East Institute in Washington, D.C., says Khamenei was an unlikely candidate. Then a midlevel cleric, Khamenei lacked religious credentials, which left him feeling vulnerable, Vatanka says.

"He knew himself. He didn't have the prestige, the gravitas to be … the successor to the founder of the Islamic Republic, Ayatollah Khomeini," he says.

"He spent the first few years in power being very nervous," says Vatanka. "He really literally felt that somebody is going to, you know, take him down from the position of power."

But Khamenei was cunning and able to outwit other senior political figures in the Islamic Republic, according to Ali Vaez, director of the Iran Project at the International Crisis Group. He says that with the help of the formidable Islamic Revolutionary Guard Corps, Khamenei built up his power base to become the longest-serving leader in the Middle East.

"Ayatollah Khamenei was a man with strategic patience and was able to calculate a few steps ahead," he says. "That's why I think he managed — on the back of the Revolutionary Guards — to increasingly appropriate all the levers of power in his hands and sideline everyone else."

Khamenei's close ties to the Revolutionary Guards allowed Iran's military to develop a vast commercial empire in control of many parts of the economy, while ordinary Iranians struggled to get by.

Vaez says Khamenei also began to build up Iran's defensive policies, such as developing proxies like Hezbollah in Lebanon and Hamas in the Gaza Strip to deter a direct attack on Iranian soil.

"And then also becoming self-reliant in developing a viable conventional deterrence, which took the form of Iran's ballistic missile program," Vaez says.

As supreme leader, Khamenei also had the final word on anything to do with Iran's nuclear program.

Over time, Khamenei increasingly injected himself into politics. Such was the case in 2009, when he intervened in the presidential election to ensure that his favored candidate, the controversial conservative Mahmoud Ahmadinejad, won office.

Iranians took to the streets to protest what was widely seen as a fraudulent election. Khamenei brutally crushed those demonstrations, triggering both a backlash and more protest movements over the years.

Iran killed thousands of its citizens under Khamenei's rule, including more than 7,000 people killed during weeks of mass protests that started in late December 2025, according to the Human Rights Activists News Agency, a U.S.-based organization that closely tracks rights abuses in Iran.

"Khamenei had always supported and endorsed repressive government crackdown, recognizing that these protests were damaging to the stability and legitimacy of the state," says Sanam Vakil, an Iran expert at Chatham House, a London-based think tank.

But Khamenei was unconcerned about getting to the root of the protests, says the Middle East Institute's Vatanka, and remained stuck in an Islamic revolutionary mindset against the West.

"He on so many occasions refused point-blank to accept the basic reality that where he was in terms of his worldview was not where the rest of his people were," Vatanka says.

He adds that 75% of Iran's 90 million people were born after the revolution and have watched other countries in the region modernize and integrate with the international community.

"The 75% he should have catered to, listened to and address[ed] policies to satisfy their aspirations," he says. "He failed in that miserably."

The International Crisis Group's Vaez says after the Arab Spring uprisings in 2011, Khamenei did start worrying about the survival of his regime. Iran's economy was crumbling, due in large part to stringent Western sanctions, fueling more unrest.

In 2013, Khamenei agreed to secret negotiations with the U.S. about Iran's nuclear program, which eventually led to the 2015 Joint Comprehensive Plan of Action nuclear agreement. Vaez says Khamenei deeply distrusted the U.S. and was skeptical about the deal.

"His argument has always been that the U.S. is always looking for pretexts, for putting pressure on Iran," he says. "And if Iran concedes on the nuclear issue, then the U.S. would put pressure on Iran because of its missiles program or because of human rights violations or because of its regional policies."

President Trump's withdrawal from the nuclear deal during his first term in office gave some credence to Khamenei's cynicism. Analysts say Iran increased its nuclear enrichment after that to a point where it was close to being able to build a bomb.

In early 2025, when Trump reached out to Iran about a new deal, Khamenei dragged out negotiations until they began in mid-April.

But time ran out. In June, Israel made good on its threat to neutralize Iran's nuclear program, launching strikes on key facilities and killing scientists and generals. Iran retaliated, and the two sides exchanged several days of missile strikes.

On June 21, 2025, the U.S. launched major airstrikes on three of Iran's nuclear enrichment sites. Trump said the facilities had been "completely and totally obliterated," although there was debate among the White House and nuclear experts as to how serious Iran's nuclear program had been set back.

Vakil, of Chatham House, says Khamenei underestimated what Israel and the U.S. would do.

"I think that Khamenei always assumed that he could play for time, and what he really didn't understand is that the world around Iran had very much changed," she says. "The world had tired of Khamenei and Iranian foot-dragging and antics … and so that was a miscalculation."

But it was Iran's use of proxy militias across the region that eventually led to Khamenei's downfall.

When Hamas — the Palestinian Islamist group backed by Iran — attacked Israel on Oct. 7, 2023, killing nearly 1,200 people and kidnapping 251 others, it triggered a cascade of events that ultimately led to Israel's attack on Iran. 

The day after the 2023 Hamas-led attack, Iran-backed Hezbollah in Lebanon started firing rockets into Israel, triggering a conflict that led to the Shia militia's top brass being decimated — including top leader Hassan Nasrallah.

Israel and Iran traded direct airstrikes for the first time in 2024 as part of that conflict.

Israel's bombing of Iranian weapons shipments in Syria also helped weaken the regime of Syria's then-dictator, Bashar al-Assad, an important ally of Iran. Assad fell in December 2024 and fled to Russia in early January 2025.

By the time Khamenei died, his legacy was in tatters. Israel had hobbled two key proxies, Hamas and Hezbollah, and had wiped out Iran's air defenses. With U.S. help, it left Iran's nuclear program in shambles.

What remains is a robust ballistic missile program, the brainchild of Khamenei. It's unclear who will replace him to lead a now weakened and vulnerable Iran.