Who was Hamas leader Yahya Sinwar?

Yayha Sinwar has been a central figure in Hamas for decades, and the most pivotal person behind the Oct. 7, 2023, attack on Israel and the bloody conflict in Gaza that has followed in the year since then.

A short wiry man with close cropped hair that is now white, Sinwar was known for his obsessive levels of secrecy and security precautions, and was labeled a psychopath by Israeli politicians and security officials.

Sinwar’s death in an Israeli assault in Gaza fulfilled a promise made by Israeli leaders made last year, including Defense Minister Yoav Gallant, who swore they would assassinate him in retribution for the wave of killings and hostage-taking that horrified Israel a year ago.

Sinwar was widely believed to be responsible for the decision to take captives back to the Palestinian territory, in a move that has irrevocably changed the course of Israeli-Palestinian history.

He had spent more than two decades inside Israeli prisons, before winning his freedom 12 years ago in a hostage ransom deal of the kind he hoped to broker during the current conflict.

Last year’s Oct. 7 attack won Hamas support among many Palestinians, many of whom regard it as resisting decades of Israeli subjugation.

In the past 12 months, most Palestinians and Israelis imagined Sinwar had been staying largely underground in some part of the extensive tunnel network that has bedeviled the Israeli military as it has operated inside Gaza.

But his role during repeated rounds of on-again, off-again cease-fire talks between Hamas and Israel — brokered by the United States, Egypt and Qatar — provided him with significant influence, as he continued trying to outmaneuver Israel, and survive.

Born on Oct. 29, 1962, according to Hamas, Sinwar helped found the group’s internal security apparatus in the late 1980s. He earned a nickname among Palestinians: the butcher of Khan Younis, where he grew up in southern Gaza. His role in Hamas for years was to help root out suspected Palestinian informants for Israel.

He was imprisoned in Israel on four life sentences in 1988, accused of playing a role in killing Israeli soldiers and four suspected Palestinian collaborators with Israel.

“He [has] so many secrets,” says his former prison mate, Esmat Mansour, who now serves as a commentator of current affairs in Arabic-language media.

Mansour recalls that Sinwar had assembled a small team of confidants who would smuggle cellphones into prison, interrogate new prisoners about how they had been caught preparing an attack against Israel, and catch Palestinian inmates serving as informants for Israel.

“So many spies,” Mansour said during a conversation with NPR in the Palestinian city of Ramallah.

In 2006, Israeli soldier Gilad Shalit was captured by Hamas and held hostage in Gaza for five years. The man who guarded the captive soldier was none other than Sinwar’s own brother, Mohammed.

In 2011, Hamas freed the captive soldier in exchange for more than 1,000 Palestinian prisoners. Sinwar’s brother made sure Sinwar was among them.

“All the prisoners [looked] at him as a man who can decide about their life,” Mansour says.

His VIP status in prison, and return to Gaza with the released prisoners, helped Sinwar rise the ranks to lead the Gaza branch of the group, which is designated as a terrorist organization by several nations including the United States.

But over the years, he very rarely appeared in public, meeting with groups of foreign journalists only twice, around periods of conflict with Israel.

“Your presence for us is a big accomplishment and asset for our people and our cause,” he told visiting reporters at a 2018 press conference in Gaza City that lasted two hours.

At the time, Hamas was holding two Israeli citizens and the bodies of two killed Israeli soldiers. When NPR asked Sinwar about the captives, he said it was a confidential file he wasn’t prepared to talk about.

Hamas had been encouraging violent protests along the Israeli border fence of the blockaded Gaza Strip during this period. He said it was a strategy he learned from his hunger strikes in Israeli prison, where he said Palestinian prisoners had protested better conditions from their Israeli jailers.

The strategy seemed to work.

Hamas and Israel, which do not speak directly to each other, reached an indirect arrangement known as “quiet for quiet.” Hamas agreed to cool hostilities and Israel agreed to ease Gaza’s high unemployment rate, granting coveted Israeli work permits to thousands of laborers from the territory.

A 2021 Hamas-Israel war had torpedoed that unofficial agreement. Sinwar gave another press conference to foreign media after the 2021 round of fighting, denying that Hamas had routed international humanitarian aid to its clandestine effort to build underground tunnels for Hamas fighters.

Israel’s permits for workers from Gaza resumed, and surged to higher numbers, while fighting between Gaza and Israel ceased. The number of work permits Israel granted Gaza laborers, before the current war, surpassed 8,000.

Eyal Hulata, who served as Israel’s national security adviser last year, thought this strategy bought Israel some quiet on the Gaza border.

“I don’t know. I thought we had an understanding what Sinwar’s thinking was, and this was so wrong,” Hulata told NPR in a recent briefing with journalists.

When Hamas fighters stormed the border, killed about 1,200 people and took back to Gaza at least 240 captives, according to Israeli officials, Israeli society alongside the country’s political and military elite were largely confounded, and deeply shocked.

In response, Israel’s military campaign in Gaza has killed more than 42,400 Palestinians and injured more than 99,000, according to Gaza’s Health Ministry.

Sinwar was the Gaza Strip’s leader of Hamas at the time of last year’s Oct. 7 attack. In August this year, he took over as the top political leader of the Hamas organization after the assassination of its political leader Ismail Haniyeh in Iran, presumably by Israel.

At the time, Sinwar was one of Hamas' few remaining senior officials after the assassinations of Haniyeh, deputy political chief Salah Arouri in January and top military commander Mohammed Deif in July. Israel confirmed the killing of Deif and is presumed to have carried out the other assassinations.

David Meidan, the Israeli negotiator who, along with other officials, had approved Sinwar’s release from prison in 2011 during an exchange that saw Palestinian prisoners released in return for a single Israeli captive soldier, says Sinwar’s strategy with the Oct. 7, 2023, attack was similar.

“First of all, to capture maximum hostages, and to use them as a tool to release his friends,” Meidan says.

Sinwar had been unable to secure that release of his fellow prison mates with whom he spent years behind bars in Israel. But last year, Israel did free several Palestinian women and minors jailed over the prior few years, in exchange for Hamas releasing some of the Israeli hostages taken to Gaza last October.

During that time in late November 2023, both sides agreed to a temporary cease-fire in the war. For every 10 hostages Hamas released per day, Israel extended the cease-fire another day and released 30 Palestinian prisoners and detainees.

Many Israelis worried that a pause in fighting would help Hamas fighters regroup, and leave more time for international pressure to mount against Israel resuming its military assault. But Israel renewed combat in Gaza, following a dispute over the kind of hostages Hamas offered to release and renewed Gaza rocket fire onto Israel.

Meidan said the pause in fighting had helped Sinwar buy time — which would be key to his survival. After the last Israel-Hamas war in 2021, Sinwar had dared Israel to assassinate him, and walked openly in the streets of Gaza.

That was not an approach he subsequently repeated, but he has nevertheless been killed.

Editor’s note: This is an updated version of a profile of Yahya Sinwar published on Dec. 3, 2023.