The bloodiest crisis in Iran’s recent political history started in a conservative bastion: Tehran’s market area.

Bazaar workers and other merchants historically have been some of the Islamic Republic’s most loyal supporters. They helped to propel its leaders to power in 1979, and largely sat out the mass protests that swept Iran in past years. This time, they were the ones who initiated the uprising.
They were soon joined by Iranians of all backgrounds, including the young and secular who were the driving force behind earlier waves of antiregime protests. What stood out about this wave is that it was sparked by segments of society that traditionally backed the Islamic Republic, with regime heartlands—such as the clerical center of Qom and the holy city of Mashhad—witnessing some of the largest uprisings in decades.
It is an ominous sign for the religious clerics that run Iran and reflects widespread discontent with their rule. A wave of violence that killed thousands has quashed the unrest for now but the dissatisfaction remains.
The trigger of the latest protests was the collapse in the value of the local currency, the rial, which drove up import costs and fueled inflation in an economy that was already battered by sanctions. Even middle-class Iranians were struggling to cover everyday expenses such as meat and other food. This posed a threat to many shopkeepers.
“All the shop owners closed their shops and said, ‘We can’t sell anything,’” said a 40-year-old woman who operates a clothing shop in the bazaar with her husband. He was among the first people to join the uprising in late December, when angry merchants took to the streets denouncing the paralyzed state of Iran’s economy and calling for the removal of their leaders from power.
Security forces pepper-sprayed the crowds, who responded by hurling rocks. At one point, she saw a man sitting down in the street in front of the police and shouted “Kill me, I am not afraid! We can’t live anyway!” The police rounded up dozens of people and took their phones, she said.
The woman’s husband was arrested but released the same day after she went to plead for his release in the turmoil as government forces rounded up demonstrators, she said. The merchant couple were extremely lucky. A sympathetic police chief decided to free him, she said.
“All protests need an ignition. This time, the ignition was the currency rate, which pushed bazaaris and shopkeepers around the bazaar to close their stores in protest,” said Mohsen Sazegara, a former Iranian government official turned opposition activist now living in the U.S. “Right now it’s about economic injustice. But people have many other problems with the regime. Its ideology is not accepted by the people anymore, even among my generation,” said Sazegara, who is in his 70s.
Their willingness to take to the streets also carries symbolic weight. Bazaars, traditional covered marketplaces, were vital hubs historically. They have also been a political bellwether in Iran.
Controlling at the time a large portion of Iran’s trade, import-export and foreign-exchange markets, the shop owners of the Tehran bazaar were among the first to move in the 1979 revolution.
Bazaaris provided financial support to the opposition and drew on their countrywide networks to help organize the unrest, lending decisive help to the uprising that included Iran’s mosque network, trade unions and many ordinary people.
After coming to power in 1979, Ayatollah Ruhollah Khomeini promised to “preserve” the bazaar and blamed the deposed shah of Iran for marginalizing the traditional market, parts of which are some 2,000 years old. Many bazaaris were recruited to political positions inside the Islamic Republic.
That alliance frayed over the years, with merchants blaming their leaders for their poor handling of the economy, from fueling corruption to failing to persuade the U.S. to relax sanctions.
“Even for Iranians who have no historical memory of the 1979 revolution, when the bazaar closes, when it goes on strike, it means it is a political moment that can be seized by others,” said Arang Keshavarzian, a professor of Middle Eastern studies at New York University, who wrote a book about the relationship between the bazaar and the state in Iran.
“The anger of these merchants is palpable. They want profound change. They hold the government responsible for the fact they cannot afford food, a summer holiday or that their son or daughter is unemployed,” he added.
The protests spread nationwide, reaching as far as the Persian Gulf island of Qeshm, a free-trade zone that has seldom seen any kind of political mobilization. At least 15 people were killed in Qeshm in the ensuing violence, according to Hengaw, a Norway-based human-rights group that monitors Iran.
Large antigovernment demonstrations also took place in Isfahan, a historic city that played an important role in the 1979 revolution and has been a cradle of ultraconservatives resisting social and political change to the Islamic Republic.
In recent years, the city’s business community has been hard-hit by sanctions and by a drop in the number of tourists. Adding to the discontent is a water crisis, which locals blame on the mismanagement of nearby dams.
These were some of the factors that pushed a 32-year-old construction contractor to join the antigovernment protests there earlier this month. “God willing, tomorrow or the day after that everyone comes,” the businessman said in a text message sent to a relative and seen by The Wall Street Journal.
Unlike the many young, secular Iranians who participated in the protests, the businessman regularly went to mosques for Friday prayers and kept the traditional fast during the month of Ramadan. He had also grown disillusioned with the lack of political freedom in the Islamic Republic, the relative said.
The businessman joined the protest on Jan. 8, the day authorities shut down the internet and ramped up the violence against the demonstrators. Security forces were deployed in large numbers and with lethal weapons.
Footage from that day in Isfahan shows Molotov cocktails being thrown at a state-television building, which caught fire. The videos were verified by Storyful. The businessman was critically wounded while protesting on Jan. 9, and died a day-and-a-half later, leaving behind a widow and two young children, the relative said.
Some of the biggest protests in the country took place in Mashhad, Iran’s second-largest city.
On Dec. 30, protesters gathered near the bazaar and the golden domes of the Imam Reza Shrine, an important pilgrimage site for Shiite Muslims worldwide. The protests swelled in the days that followed, with huge crowds pouring onto major roads and chanting slogans that called for the downfall of the regime. Protesters pulled down a large flag of the Islamic Republic and tore it to pieces.
Security forces responded with brutal force, firing gun shots, tear gas and stun grenades at antigovernment demonstrators, according to rights groups and a former resident who is in contact with friends and family there. Snipers shot at protesters from elevated positions.
A medical worker interviewed by Amnesty International said they saw the dead bodies of around 150 protesters in the morgue of a single Mashhad hospital on Jan. 9.
By Sunday, protesters had largely retreated to their homes and a large number of security forces patrolled the streets, sometimes carrying heavy weapons.
“The streets are now empty. Everyone is so scared,” said the former Mashhad resident.
He said his friends in Mashhad are in favor of possible U.S. strikes against the Islamic Republic. “I told them: ‘Trump is coming, be patient.’ They were happy. They were so hopeful because they thought he would come,” he said.
Write to Jared Malsin at jared.malsin@wsj.com, Margherita Stancati at margherita.stancati@wsj.com and Benoit Faucon at benoit.faucon@wsj.com