Yahya Ibrahim Hassan Sinwar was born in 1962 in a refugee camp in Khan Yunis and attended the Khan Yunis Secondary School for Boys. After high school, he attended the Islamic University of Gaza, where he graduated with a bachelors degree in Arabic studies.
While attending university in 1982, Sinwar was arrested for the first time. In prison he became friendly with Palestinian activists, and decided to dedicate himself to the Palestinian cause.
In 1985, Sinwar founded Hamas’s security branch, whose job included punishing “morality” offenders and killing Palestinians suspected of collaborating with Israel. His enthusiasm for executing collaborators led Israeli interrogators to refer to his as the “the Butcher from Khan Younis.”
In 1988, Sinwar was arrested again and sentenced to four life terms in an Israeli prison for attempted murder and causing grievous bodily harm through sabotage. During his confinement, Sinwar’s life was saved when he had brain surgery, reportedly to remove a tumor.
Sinwar was released in 2011, one of a total of 1,000 Palestinian prisoners exchanged for a single Israeli soldier, Gilad Shalit, who was captured in 2006 and held hostage in Gaza for five years by Hamas. Sinwar was the most senior prisoner released. He said he devoted his time in jail to studying his enemy.
Sinwar is believed to be responsible for the detention, torture and killing of a Hamas commander, Mahmoud Ishtiwi, who was initially held for embezzlement in 2015. Later, after he was murdered, Ishtiwi was accused of committing “moral crimes” – amid suspicions of gay sex — that Mr. Sinwar apparently feared could lead to extortion and compromise Hamas.
Al Resalah, a Hamas-affiliated newspaper in Gaza, credited Sinwar with coordinating the communications between the group’s senior commanders who were hiding from the Israelis during confrontations with the Israeli army and the Qassam Brigades.
According to Israeli sources, Sinwar is a “bitter enemy” of the Egyptians and supports working with Islamic State affiliates fighting the Egyptian Army in the Sinai Desert. He also favors closer relations with Iran.
In March 2021, Sinwar was elected to a second four-year term as the head of the organization’s Gaza political bureau in an election held in secret. He is the highest-ranking Hamas official in Gaza and the Strip’s de facto ruler. He is the second most powerful member of Hamas after Ismail Haniyeh.
Sources: Dov Lieber, “We Saved Hamas Leader's Life, Says Israel Ex-Prison Chief, Dismissing Strike Complaints,” Times of Israel, (May 11, 2017).
Isabel Kershner, “Hamas Appoints Hard-Line Militant as Gaza Leader,” New York Times, (February 13, 2017).
Aaron Boxerman, “Sinwar wins 2nd term as Hamas Gaza chief after tense election standoff,” Times of Israel, (March 10, 2021).