Mr. Talabani speaks during a news conference in 2006. (Ali Al-Saad/Reuters)

Former Iraqi President Jalal Talabani, one of the country’s most powerful and unifying leaders and a man who spent much of his life fighting for the cause of the Kurds of northern Iraq, died Oct. 3 at a hospital in Berlin. He was 83.

His death was confirmed by Sadi Ahmed Pira, a spokesman for the Patriotic Union of Kurdistan, Mr. Talabani’s political party. He had long struggled with his health and was often treated abroad. In 2008, he underwent heart surgery at the Mayo Clinic in Minnesota. He suffered a stroke in 2012 and stepped down as president in 2014.

A good-humored, portly man with a soft smile and a mustache, Mr. Talabani was nonetheless a pragmatic and savvy political operator who knew when to play down his Kurdish nationalism. He had been a frequent emissary to world capitals for the Kurdish people before and after the overthrow of Saddam Hussein in the U.S.-led invasion of 2003.

He was popularly known as Mam Jalal, Kurdish for Uncle Jalal, a nickname ascribed to him in his youth because of his seriousness and that later reflected the affection of his supporters and even some political rivals.

Mr. Talabani’s death came just days after the semiautonomous Kurdish region held a landmark referendum on whether to declare independence from Iraq. The yes vote passed by an overwhelming margin — marking a step toward a goal sought by millions of Kurds for a century or more — but it also set off the worst feud between Iraq’s central government and the Kurds since the fall of Hussein and fears that the crisis could descend into war.

Many in Iraq have wondered whether the crisis would have occurred if Mr. Talabani had still been active in politics, or if he might have been able to defuse it.

As a Kurd, Mr. Talabani was the first non-Arab president of an Arab nation. Although his office was largely ceremonial, he exerted great influence over the Iraqi political landscape.

He was able to bring Iraq’s warring factions to the negotiating table — and keep them there amid violent sectarian conflict from 2005 to 2007. He was credited with preventing the disintegration of the country’s fragile national unity government in the wake of the U.S.-led occupation.

“His biggest victory, and vindication, was to ascend to the presidency of Iraq, succeeding a dictator who had worked long and hard to eradicate the Kurdish national movement,” said Joost R. Hiltermann, a Middle East expert with the International Crisis Group, a conflict prevention organization.

“Astoundingly, as president of Iraq, Talabani worked hard not to be seen as an advocate of the Kurds but to represent Iraqis, and to a large extent he succeeded,” Hiltermann said. “Time and again he intervened and mediated in political crises, and each time, he managed to lower the temperature, helped to a great extent by his jocular and avuncular personality.”

In the years before his death, Mr. Talabani tried to mediate a deepening political crisis among Iraq’s three main groups — Shiites, Sunnis and Kurds.

As his health deteriorated, he fell from public view, and Baghdad and the semiautonomous Kurdish region hurtled toward a political impasse over revenue sharing, oil and borders. His poor health kept him out of the debate over the independence referendum, which was opposed by Iraq’s central government, the United States, Iran and Turkey.

Mr. Talabani was not without his autocratic tendencies, Hiltermann said, and failed to provide for a stable transition to new leadership.

Jalal Talabani was born Nov. 12, 1933, in Kelkan, in the Iraqi Kurdistan region. He showed an early revolutionary streak, founding the underground Kurdish Student Union when he was 13. The next year, he joined the newly formed Kurdish Democratic Party (KDP); by 18, he was a member of the party’s central committees, often forced to go into hiding because of his fight for Kurdish rights.

Nevertheless, Mr. Talabani managed to earn a law degree from the University of Baghdad in 1959. But law was his second choice — after medicine.

“I was not accepted at the College of Medicine because I did not have the so-called good-behavior certificate, which used to be issued by the security services known as the ‘criminal investigations department,’ ” Mr. Talabani told the Arab daily al-Sharq al-Awsat in 2009.

“I had been arrested several times, and even when I was in Kirkuk during my secondary education, I was arrested twice,” he said. “I was always under observation by the secret police.”

By 1961, he began to focus on the cause of Kurdish resistance against the Iraqi government. Mr. Talabani was a battlefront commander and led separatist movements in several Kurdish regions. When not on the front lines, he traveled on diplomatic missions, becoming the face of Kurdish resistance to Europeans and across the Middle East.

“You have to judge political objectives according to realistic expectations,” Mr. Talabani told the Los Angeles Times in 1991. “We don’t want to be like the Palestinians and ask for the impossible. If there were a democratic government in Iraq, we would be happy to be Iraqis.”

In 1975, Mr. Talabani and others splintered from the KDP and formed the PUK, which launched an armed resistance against Iraq’s ruling Baath Party, which in a few years Hussein would lead.

In the 1980s, tensions mounted between Mr. Talabani and KDP leader Massoud Barzani, even as the PUK resisted Hussein’s regime. In 1994, armed conflict erupted between the two Kurdish parties. Four years later, the feuding factions signed a peace deal that called for them to jointly govern Iraq’s Kurdish regions.

When Hussein launched a crackdown on the Kurdish separatists in the late 1980s, using chemical weapons that killed thousands of Kurds, Mr. Talabani sought refuge in Iran, from where he continued the struggle for Kurdish independence.

Mr. Talabani played a key role in uniting the Kurds to help the U.S.-led coalition topple Hussein.

During the 1991 Persian Gulf War, tens of thousands of Kurdish troops advanced to within 90 miles of Baghdad. But U.S.-led forces had been ordered not to overthrow Hussein after pushing his troops out of Kuwait. In the war’s aftermath, Hussein launched an intense military assault against the Kurds, but President George H.W. Bush decided not to intervene.

“I am very surprised and astonished to see that the United States is now indifferent to the fate of the Iraqi people,” Mr. Talabani told the Boston Globe at the time. “The Americans, they stopped the war, and the Iraqi people now have to struggle to end the war alone. I sometimes hear rumors — I don’t believe them — that the United States is content to have Saddam Hussein in power.”

For the next decade, Mr. Talabani would continue to lobby for the overthrow of Hussein. Months before the 2003 Iraq invasion, Mr. Talabani offered to allow U.S. forces to use Kurdish territories as a springboard to attack the regime.

Mr. Talabani helped build a political footprint in the new Iraq. He and his old rival Barzani forged a new pact promising closer cooperation to run the Kurdish regions.

In October 2002, the Kurdish parliament reconvened for the first time in six years; Mr. Talabani and Barzani each apologized to the other’s followers, endorsed a U.S.-backed peace plan and pledged to support a draft constitution that would lead to the creation of a Kurdish nation. A few months later, both leaders agreed to lead the Iraqi Kurdistan region jointly.

Mr. Talabani was conscious of the impact of world opinion.

In April 2003, he and Barzani sat down to lunch with a group of journalists, according to a Newsday account. Both leaders patted the other on the back, smiled and joked. As the waiters brought plate after plate of delicious dishes, Mr. Talabani asked a photographer not to take any photos.

“We want to give the world an image of the Kurds as a suffering people,” he said, with a smile. “This feast will not do it.”

An alliance of Kurdish parties, led by Mr. Talabani and Barzani, won 75 parliamentary seats in Iraq’s January 2005 elections. That April, Mr. Talabani was elected president by the country’s transitional National Assembly.

Exhibiting his skills as a mediator, one of Mr. Talabani’s first acts as president was to reach out to Iraq’s Sunnis and offer an amnesty to woo them away from the spreading insurgency.

“We should find the political and peaceful solutions with those Iraqis who were deceived into joining the terrorists to afford them amnesty and invite them to join the democratic process,” Mr. Talabani said at the time.

The Iraqi parliament reelected him the next year and again four years later in November 2010.

Survivors include his wife, Hero Ibrahim Ahmed, and two sons, including Qubad Talibani, a former representative of the Kurdistan Regional Government in the United States and now deputy prime minister of the KRG.

Tamer El-Ghobashy in Cairo, Mustafa Salim in Baghdad, and Kareem Fahim and Aaso Ameen Schwan in Irbil, Iraq, contributed to this report.