On Tuesday, as Ismail Haniyeh visited Iran’s parliament for the inauguration of the Islamic Republic’s new president he was embraced and hailed as a hero of the resistance against Israel. 

Just hours later, however, the veteran Palestinian leader was killed when a projectile hit the building in which he was staying.

Born in 1962 in the Shati refugee camp, near Gaza City, after his parents were displaced from their Ashqelon home during the Nakbah, he rose to become a confidant of Hamas’s founder, a powerful political leader in his own right, and a billionaire. 

As a teenager, Haniyeh gained his first-hand knowledge of Israel by working as a construction worker.

Taking advantage of the then-open border between Gaza and the Jewish state in the late 1970s, the 16-year-old Palestinian took a job as a labourer in the town of Ashkelon.

"I knew him as a worker who only knew how to make plaster,” recalled Israeli builder Danny Makhlouf to Maariv, an Israeli newspaper, in 2018.

“I taught him to work, he worked with me for nine years. [He was] the best person in the world. He is honest and smart and not stupid. He was a member of the family, he was also at my daughters' weddings.” There was no indication at the time that he would go on to take a leading role in Hamas.

Haniyeh next studied Arabic literature at the Islamic University of Gaza, where he first became involved in Islamist politics.

Initially a member of the Islamic Student Bloc, a precursor to Hamas, he graduated in 1987 as the First Intifada was launched against Israel’s presence in the West Bank and Gaza.

As Palestinians carried out a campaign of civil disobedience and riots, Haniyeh was arrested and held for 18 days.

The same year, Ahmed Yassin, a hardline wheelchair-bound cleric, founded Hamas. Haniyeh joined the fledgling movement and was jailed again: first for six months, and then, from 1989, for three years.

Haniyeh was embraced by Iranian lawmakers when he attended Masoud Pezeshkian's inauguration (Photo: Getty Images)

On his release, he was deported by Israel to southern Lebanon alongside 415 other members of the terror group.

Haniyeh would return to Gaza a year later following the signing of the first Oslo Accords to be appointed dean of the Islamic University.

Having served the Islamist resistance movement in prison, exile and academia, it was at this point that his star began to rise. 

Haniyeh became a close confidant and aide of Yassin in 1997 before, in 2001 amid the Second Intifada, establishing himself as one of Hamas's political leaders.

In 2003, he survived the first attempt to assassinate him, when he and Hamas’s founder were targeted by an Israeli airstrike against an apartment block in Gaza City in which the men were meeting.

Six months later, the IDF succeeded in killing Yassin, before slaying his successor, Abdel-Aziz Rantissi, shortly after.

With Hamas afraid of continued Israeli assassination attempts, Haniyeh was secretly appointed to Hamas’s collective leadership group alongside Mahmoud Zahhar and Said al-Siyam.

In 2006, when Hamas violently overthrew their rivals, Fatah, and took power in Gaza’s legislative elections, Haniyeh was appointed prime minister of the Gaza Strip.

After just a year, however, he was dismissed by Palestinian Authority leader Mahmoud Abbas and a brief civil war broke out in the enclave.

After defeating and expelling Fatah, Hamas would rule Gaza under Haniyeh’s leadership with an iron grip.

During his time in office, he greatly developed the group’s military capabilities, expanded an extensive tunnel network under the Strip, and built up its relationship with the Iranian regime.

Before moving to Qatar, Haniyeh lead Hamas in the Gaza Strip (Photo: Getty Images)

Speaking to Sky News in 2016, he declared: “It is difficult to break the will of the people of Gaza, they can handle the siege… We are preparing to defend the Palestinian people with all our resistance."

In 2017, he formally assumed the political leadership of Hamas when he took over the role from Khaled Meshaal.

Based from that point in Qatar, Haniyeh led diplomatic efforts for the Islamist movement, deepening its connections with the Turkish government, speaking at the funeral of Qassem Soleimani, the IRGC figure killed in an American strike, and calling for a new intifada against Israel.

Viewed by some as a pragmatist who rejected the more hardline position of Hamas’s Gaza-based military leadership, Haniyeh nonetheless expressed his support for the October 7 attack, and footage showed him celebrating in his hotel suite in Qatar.

“How many times have we warned you that the Palestinian people have been living in refugee camps for 75 years, and you refuse to recognize the rights of our people,” he said in its aftermath.

In May, the International Criminal Court’s chief prosecutor asked for a warrant for his arrest, alongside Hamas’s leader in Gaza, Yahya Sinwar, the leader of its Al-Qassam Brigades, Mohammed Deif, and Israel's Benjamin Netanyahu and Yoav Gallant.

He bore responsibility, Karim Khan KC said, for the taking of hostages, rape, and extermination as a crime against humanity.

"It is the view of my office that these individuals planned and instigated the commission of crimes on 7 October 2023, and have through their own actions, including personal visits to hostages shortly after their kidnapping, acknowledged their responsibility for those crimes,” he wrote.

"We submit that these crimes could not have been committed without their actions.”

In the months following October 7, Haniyeh represented Hamas during ceasefire and hostage release negotiations.

During Israel’s campaign in Gaza, meanwhile, the terror leader’s own family was targeted by the IDF

Three of Haniyeh’s sons – Hazem, Amir and Mohammad and four of their children – were killed in April when an Israeli airstrike struck their car.

“Whoever thinks that by targeting my kids during the negotiation talks and before a deal is agreed upon that it will force Hamas to back down on its demands, is delusional,” Haniyeh insisted at the time.

“All our people and all the families of Gaza have paid a heavy price in blood, and I am one of them.”

Experts are now divided on the exact consequences of Hanieyh’s killing, and to what extent it will hinder Hamas.

Mourning his death on Wednesday, Hamas said: “The Islamic Resistance Movement Hamas mourns the sons of our great Palestinian people, the Arab and Islamic nation, and all the free people of the world.”