Woman. Life. Freedom. Those are the words being chanted by the thousands of anti-government protesters taking to the streets across Iran in response to the death of 22-year-old Mahsa Amini. The young woman died while in the custody of the Gasht-e Ershad — the country’s “morality police” — who detained Amini for violating Iran’s hijab law, which mandates veiling for women and modest Islamic dress. Despite the government’s insistence that Amini died of a preexisting heart condition, Iranians widely believe that the morality police beat her to death.

While Amini’s death was the spark that ignited the protests, the roots of unrest stretch back decades. At its heart, the current uprising is about the Islamic Republic’s four decades of patriarchal oppression and violence against women, as well as the determined resistance of Iranian women to that oppression.

While Mohammad Reza Pahlavi’s government, which ruled Iran from 1941 to 1979, was repressive, women in Iran made significant gains during his rule. They had access to higher education, careers, the right to vote and hold office (admittedly a dubious right in an undemocratic country), equal pay laws, health care and reproductive rights, and a cabinet-level position dedicated to women’s issues — only the second such position in the world. Women could choose how they dressed. Because of women’s activism, Iran’s 1967 Family Protection Law — and a subsequent 1975 amendment — was one of the most liberal such laws in the Islamic world. It mandated more equitable marriage, divorce and inheritance rights for women and largely eliminated polygamy.

Although many women participated in the uprising that toppled the shah’s regime, controlling and subordinating women was at the top of the new Islamic Republic’s agenda from the moment of its inception in 1979. Ayatollah Ruhollah Khomeini, the fundamentalist Shiite cleric who was the symbolic leader of the revolution, saw women’s equality as incompatible with the strict Islamic society he sought to create.

On March 6, 1979, just weeks after the shah fled the country and two days before International Women’s Day, Khomeini declared that he wished to overturn the Family Protection Law and that all women must wear the chador, Iran’s traditional form of Islamic veil that covers a woman’s hair and body. In response, tens of thousands of Iranian women marched in protest across the country for three days. Because Khomeini still shared political power with pro-democracy liberals like Prime Minister Mehdi Bazargan, the protests caused him to temporarily back down and rescind the declarations.

But in 1980, after Khomeini consolidated power, he once again ordered compulsory veiling and fired all female judges. Female protesters again took to the streets, but they could not stop Khomeini’s agenda. The Islamic Republic officially enshrined compulsory veiling into law in 1983, along with other restrictions on women’s rights.