On an early autumn day in Tehran, moral police arrested a 22-year-old Iranian woman in a city park who was visiting family in the capital, put her in a van and drove her to the police station.

The arrest of Mahsa Amini on September 13 started a chain of events that a month later has presented Iran’s spiritual leadership under Supreme Leader Ayatollah Ali Khamenei, 83, with one of the greatest challenges since the 1979 Islamic Revolution, whose final outcome is still a long way off, however.

Amini’s arrest was an ordeal shared each year by hundreds of women believed to have flouted the Islamic Republic’s strict dress code imposed after the Shah’s fall.

But less than two hours after her arrest and transfer to the Vozara detention center, Amini was in a coma. She was taken to Kasra hospital and pronounced dead on September 16. Her family and lawyers believe she received a fatal blow to the head while in detention.

Protests began on September 16 after the announcement of her death outside the hospital. Her funeral in her home province of Kurdistan on September 17 turned into a protest that saw the movement spread across the country.

A month later, the Iranian leadership is still faced with the most consistent, taboo-breaking and multi-faceted protest movement in the history of the Islamic Republic, as well as the first women-led protest movement.

The leaderless protest movement doesn’t seem to be waning yet, with protests taking place not only in the streets but also at universities, schools and even oil refineries.

But the regime is also ready to use repressive tools ranging to deadly force, internet shutdowns and mass arrests.

While the protests could mark “the beginning of the end of the Islamic Republic,” they must be sustained and find some sort of governance structure, said Cornelius Adebahr, nonresident fellow at Carnegie Europe.

“It just takes a lot more than continued street protests and calls for sanctions for positive change to take hold,” he said.

The protests built on existing disillusionment with economic hardship and corruption, which had led to demonstrations in the past.

They took place in Tehran, the northern center of Tabriz, the historical cities of Isfahan and Shiraz, the pilgrimage city of Mashhad, the home region of Khamenei, and the Caspian Sea provinces.

Iran has seen waves of protests in recent years – notably in 2009 over disputed election results and in 2019 over a sudden energy price hike – but none that have so openly challenged the very foundations of the Islamic Republic founded by Ayatollah Ruhollah Khomeini in 1979.

“The uprising began in response to restrictions on women’s dress and behavior in public … but has evolved into a campaign to overthrow the regime entirely,” said US-based think tank Soufan Center.

Anti-regime slogans like “death to the dictator” are not entirely new in Iran, but they have never been used more frequently.

Women have taken off headscarves and even burned them. Images of Khamenei and regime icons, such as the late Revolutionary Guards commander Qasem Soleimani, were defaced or set on fire.

Videos have shown protesters fighting back security forces, evading arrest, setting police cars on fire and even occasionally setting up roadblocks.

The deaths of young women in the protests such as Nika Shahkarami and Sarina Esmailzadeh, both 16, whose families say they were killed by security forces, has created new protest icons alongside Amini.

The protests have also shattered any perception of Iranian politics as a struggle between so-called reformist and conservative elements working within the system, and also diverted international attention from talks with Iranian leaders about the nuclear program.

“The protesters have changed the dominant discourse by demanding real change. They say no to the entire political regime,” said Shadi Sadr, director of the UK-based NGO Justice for Iran.

She said the current protests are “much bigger and lasted much longer” than 2019, when fewer cities were involved, including Tehran, and the protesters were mostly from lower social classes.

It was “time to think beyond the Islamic Republic,” said Roham Alvandi, associate professor at the London School of Economics, declaring that “reform is dead.”

But as in 2009 and 2019, authorities also resorted to violence, with Oslo-based group Iran Human Rights saying authorities killed at least 108 people in the Mahsa Amini wave of protests across Iran.

In addition, at least 93 people have been killed in the crackdown on protests in the southeastern city of Zahedan sparked by the reported rape of a teenager by a police chief.

According to Amnesty International, the protests are being “brutally put down” by firing live ammunition and metal bullets at protesters at close range.

Meanwhile, the persecution of protesters and opponents of the regime has been relentless, with dozens of prominent activists, journalists, lawyers and even athletes arrested and most still in prison.

After the Arab Spring, few anti-government uprisings around the world have managed to defeat authoritarian regimes.

Syrian President Bashar al-Assad remains in power more than a decade after the start of the civil war that began with rebellion against his rule.

Belarusian leader Alexander Lukashenko faced unprecedented mass protests in 2020 after an election opponent claimed he had been rigged, but stayed in power after winning support from security forces and Russia.

“Examples from the last decade of attempts to overthrow a ruthless dictator … are not particularly encouraging,” Adebahr said.

“Precisely because of the anti-system slogans being chanted at these demonstrations, the Iranian regime is determined not to budge an inch,” he said.