Ismail Haniyeh was killed in Tehran early Wednesday in an apparent assassination. Here’s what to know about the longtime leader of Hamas’s political wing, whose operations were conducted from the Qatari capital, Doha.

       Haniyeh led Hamas’s 15-member political bureau since 2017, the pinnacle of his long career with the group, which was founded in 1987. He was first appointed assistant to Hamas’s founder, Sheikh Ahmed Yassin, in 1997.

       Yehiya Sinwar, the group’s leader in Gaza, and its military chief, Mohammed Deif — who was targeted in an Israeli strike earlier this month — prefer to stay in the shadows. Haniyeh, who was considered one of Hamas’s more politically pragmatic leaders, has in recent years been the public face of the group, traveling to meet with foreign leaders. He had lived in Qatar since 2020, according to the Council on Foreign Relations.

       Yassin and Haniyeh were both injured in an Israeli strike on Gaza City in 2003. The following year, Israel killed Yassin and Hamas’s next leader in quick succession, leaving Haniyeh to join a new collective leadership.

       While Hamas historically boycotted elections, Haniyeh supported the party’s participation in the 2006 legislative elections. Hamas, led by Haniyeh, went on to win the elections amid widespread frustration with the Ramallah-based Palestinian Authority, dominated by rival party Fatah.

       Haniyeh served as Palestinian Authority prime minister in a brief unity government that followed; however, in 2007, Hamas ousted the Palestinian Authority in a short civil war and seized control of Gaza. The Palestinian Authority maintains control of parts of the Israeli-occupied West Bank. Neither group has held democratic elections in the years since.

       Haniyeh led Hamas within Gaza until 2017, when he was promoted to political leader of the larger organization (which has branches for Gaza, the West Bank, the diaspora and among Palestinians detained in Israeli prisons). He was succeeded in his previous role by Sinwar.

       One of Haniyeh’s key roles was to oversee the group’s financial operations, drawing from sources including taxes on Palestinians in Gaza and fees on black-market smuggling that proliferated amid the Israeli blockade. U.S. officials estimate Hamas has an investment portfolio worth more than $500 million, and possibly as much as $1 billion, with assets in countries such as Sudan, Turkey, Saudi Arabia, Algeria and the United Arab Emirates. It also has other international funding sources, including Iran.

       In 2018, the U.S. State Department placed Haniyeh on its Specially Designated Global Terrorists list, which triggers economic sanctions. “Haniyeh has close links with Hamas’ military wing and has been a proponent of armed struggle, including against civilians,” it said at the time. “He has reportedly been involved in terrorist attacks against Israeli citizens.”

       The International Criminal Court’s prosecutor sought an arrest warrant for Haniyeh in May, along with Sinwar and Deif, for charges of war crimes and crimes against humanity including murder, rape, torture and taking hostages, during and since the Oct. 7 attack on Israel. (Warrants for Israeli Prime Minister Benjamin Netanyahu and Defense Minister Yoav Gallant were also sought.)

       Haniyeh was born in January 1963, according to the Hamas media office, in the Shati refugee camp near Gaza City. His parents were refugees of the 1948 Arab-Israeli war, fleeing from a destroyed Palestinian village near what is now the city of Ashkelon in Israel, according to the media office.

       Israel imprisoned Haniyeh for six months in 1988, and for three years in 1989, for participating in the first intifada, a mass uprising of Palestinians against Israel. Israel deported him and some 400 other Hamas and Palestin Islamic Jihad members to Lebanon upon his release. He returned to Gaza in 1993 amid a détente between Israelis and Palestinians with the Oslo peace process, and became dean of the Islamic University, where he had earlier studied Arabic literature.

       Israeli airstrikes have killed several of his close family members — including three of his sons, at least two of his grandchildren, and his sister and her family — in recent months.

       In 2014, his home in Gaza was destroyed in an Israeli strike.

       Miriam Berger and Rachel Pannett contributed to this report.