Nawal El Saadawi, the pioneering Egyptian feminist author, has died at 89 after a long illness, the New York Times reports.

Saadawi was born in Kafr Tahla, Egypt, and earned a medical degree from Cairo University. She worked as a physician in her hometown. She wrote short stories and novels before making her nonfiction debut with the landmark book Women and Sex, which argued against female genital mutilation; she lost her job in Egypt’s Ministry of Health as a result.

In 1981, she was imprisoned for three months by Anwar Sadat, Egypt’s president at the time, because she was critical of his administration.

Saadawi was the author of dozens of books, including Memoirs of a Woman Doctor, The Hidden Face of Eve, and The Innocence of the Devil.

Saadawi was remembered by admirers on social media. On Twitter, author Elif Shafak wrote, “I can never forget Woman at Point Zero. Such a sad loss for our region, our world. Rest in peace, rest in power, sisterhood and books.”

And Palestinian activist and scholar Hanan Ashrawi tweeted, “The passing of Nawal El Saadawi deprives the Arab world, [and] Arab women in particular, of a remarkable feminist fighter, a pioneer who exposed gender power politics [and] the imperative of resistance. An activist, philosopher, writer Nawal was an irresistible force for defiance [and] change.”

Michael Schaub is a Texas-based journalist and regular contributor to NPR.