HARARE, Zimbabwe >> Robert Mugabe — who has ruled Zimbabwe since independence in 1980 and once proclaimed that “only God will remove me!” — resigned as president today shortly after lawmakers began impeachment proceedings against him.

The speaker of the Parliament, Jacob Mudenda, read out a letter in which Mugabe said he was stepping down “with immediate effect” for “the welfare of the people of Zimbabwe and the need for a peaceful transfer of power.”

Lawmakers erupted into cheers, and jubilant residents poured into the streets of Harare, the capital. It seemed to be an abrupt capitulation by Mugabe, 93, the world’s oldest head of state and one of Africa’s longest-serving leaders.

“It’s the best thing that’s ever happened to Zimbabwe,” Perseverance Sande, 20, said in central Harare minutes after news of the resignation began spreading, as crowds of people started singing around her. “I’ve been waiting so long for this moment.”

Mugabe, who controlled the nation by handing out the spoils of power to his allies and crushing dissent, had refused to step down even after being expelled on Sunday from ZANU-PF, the political party he had led for four decades.

Today, party members introduced a motion of impeachment, invoking a constitutional process that had never before been tested.

The party’s political rival, the Movement for Democratic Change, seconded the motion, a striking sign of the consensus in the political class that Mugabe must go — one that formed with astonishing speed after the military took Mugabe into custody last Wednesday.

Lawmakers were still discussing the impeachment motion when Mugabe’s justice minister, Happyton Bonyongwe, walked up to the stage. He was booed, because of a rumor that he had been offering bribes to sway votes against impeachment. Then he whispered into the ear of Mudenda, the speaker, and handed him a letter.

Calling the lawmakers to order, the speaker announced that he had received an urgent communication from the president. As the crowd grew quiet, Mudenda — with a wide smile across his face — read out the letter.

Lawmakers immediately screamed and shouted. Once-bitter rivals from ZANU-PF and the Movement for Democratic Change shook hands and hugged.

Even Mugabe’s closest allies appeared taken aback. Reached by telephone, George Charamba, the president’s longtime spokesman, declined to comment, saying only, “I’m concerned about the stability of my country.”

In Africa Unity Square, the capital’s main public area, scattered shouts were heard a few minutes after the announcement by the speaker. Then, as word began spreading by mouth and by phone, the shouts, cries and honking of cars rose in a deafening crescendo. Hundreds of people ran to the square, hugging and jumping, as the crowd soon swelled into the thousands.

“I’m happy,” said Presca Nzendora, 32, a street vendor who was hugging a friend, jumping up and down. “Bob has resigned! We were starving because of him.”

Bryan Moyo, 30, who works in internet security, ran into the middle of the square in his dark suit and red tie. “Thirty-seven years is not a joke,” he said. “He’s the only president I’ve ever known. It’s indescribable. It’s been hell. I feel like we’ve been liberated a second time.”

Nicholas Nyamaka, a 65-year-old taxi driver, said, “I used to think it would never come. It’s a dream come true. So finally the suffering is over.”

The state broadcaster interrupted its programming to report that Mugabe had resigned and that a new leader could be sworn in as early as Wednesday. Emmerson Mnangagwa, the vice president whom Mugabe abruptly fired last week, setting off an internal revolt, is widely expected to lead the country, at least until national elections scheduled for next year.

For nearly four decades, Mugabe ruled through a heavy mix of repression of his opponents and rewards for his allies. He oversaw the massacre of thousands of civilians in the 1980s and outmaneuvered rivals in his party and in the opposition. Even in his 90s and weakened by age, he kept potential successors at bay.

But he pushed too hard by trying to position his wife, Grace, 52, as his successor. Despite being a newcomer to politics who had no role in the nation’s liberation war, she made clear that she wanted to be president and ridiculed politicians who had been waiting decades to succeed her husband.

The chain of events leading to Mugabe’s downfall started Nov. 6, when he fired Mnangagwa, clearing the way for Grace Mugabe to take over the presidency at some point. Robert Mugabe then tried to arrest the nation’s top military commander a few days later.

After the military took Mugabe into custody, ZANU-PF expelled him as its leader Sunday. But Mugabe stunned the nation that evening with a televised address in which he refused to step down as president. Pressure from within the country and from abroad had been building on Mugabe to resign, but observers had warned that the country might have to brace itself for lengthy impeachment proceedings.

The motion of impeachment introduced today alleged, among other things, that Mugabe had violated the constitution; that he had allowed his wife to usurp power; and that he is too old to fulfill his duties.

Earlier today, Mnangagwa, whose firing led to a military takeover of Zimbabwe and efforts to oust Mugabe, broke his silence, urging the embattled leader to step down.

“He should take heed of this clarion call by the people of Zimbabwe to resign so that the country can move forward and preserve his legacy,” Mnangagwa said.

Mnangagwa’s role as the likely successor to Mugabe has raised many concerns. He was accused of orchestrating the crackdown in the 1980s in which thousands of members of the Ndebele ethnic group were killed. He was also accused of being behind deadly violence in 2008 a bid to rig polls in favor of Mugabe, a claim he denies.

At least a semblance of legitimacy — especially for a government under Mnangagwa, who is known as the enforcer of some of Mugabe’s most ruthless policies — will be critical in gaining recognition from regional powers, Western governments and international lenders.

Zimbabwe, which no longer has its own currency and perennially struggles to pay government workers, became a pariah in the West after the state-backed invasion of white-owned farms in the early 2000s.

Prime Minister Theresa May of Britain, Zimbabwe’s former colonial ruler, welcomed news of Mugabe’s departure, saying it presented ” an opportunity to forge a new path free of the oppression that characterized his rule.”

The U.S. Embassy in Zimbabwe issued a statement welcoming “an historic moment” for the country and urged “unwavering respect for the rule of law and for established democratic practices.” It said that “the path forward” must lead to free, fair and inclusive elections.

With the end of the Mugabe era, some who have found themselves on the losing side of history were quickly readjusting their positions.

Reached by phone, Philip Chiyangwa, a nephew of Mugabe and an ally of the president’s wife, Grace, said: “It’s fantastic! It’s the best news in 37 years!”

In an interview with The New York Times in 2016, Chiyangwa said he was a member of G-40, the faction that had been led by Grace Mugabe. But on Tuesday night, he denied ever having been a member.

“No, no,” said Chiyangwa, who is one of the country’s most prominent businessmen and also president of the Zimbabwe football association.

Chiyangwa said he had never benefited from his family connection to Robert Mugabe.

“Yes, we’re related,” he said. “But being related does not necessarily mean there was any economic relations between us — none at all.”

Tonight it was unclear what guarantees Mugabe and his family had received in return for resigning — whether they had been granted immunity, would be allowed to live in the country or keep their wealth.

In recent days, there had been indications that some allies of Grace Mugabe had been allowed to leave the country. Jonathan Moyo — a leader of Mugabe’s G-40 faction — said in a tweet Monday that he had left the country along with 50 other people. He quickly deleted it.

While Mugabe’s resignation caused immediate jubilation in the streets and among lawmakers, for many the reaction was more complex. Mugabe had occupied a central role in the nation’s four-decade history and in its founding mythology, which all Zimbabweans are taught in primary school. He was a tyrant, many said, but he was also the nation’s father figure.

Even as military leaders met Mugabe in recent days before the cameras, their body language showed extreme deference. His fiercest critics saved their harshest words for Mugabe’s wife and her political allies, often describing the president, who has become visibly frail in the past two years, as a victim of the people surrounding him.

Christopher Mutsvangwa, the head of the war veterans association and one of Mnangagwa’s closest allies, led efforts to remove Mugabe from power. But as ZANU-PF lawmakers met separately before Parliament convened, he sometimes sounded melancholy about Mugabe, with whom he had worked decades before a falling out last year.

Mutsvangwa, who once served as Zimbabwe’s ambassador to China, compared Mugabe and his wife to Mao Zedong and Jiang Qing, the Chinese leader’s fourth wife, who, toward the end of Mao’s life, assumed great power.

“He’s a traumatized old man,” Mutsvangwa said of Mugabe.

Even among the celebrants in Unity Square, some wore quiet, almost sad expressions.

David Mushakwe, 35, a car electrician, stood quietly as he watched hundreds of mostly young men jumping on trucks on the edge of Unity Square, in front of Parliament. Lawmakers had met in the building in the morning and then moved to a hotel in another section of the city for a joint session of Parliament in the afternoon.

“I just want to say to His Excellency: ‘Go and rest now, our father,’” Mushakwe said. “‘We still love you. But we’re happy today. We’re hoping now for a better future.’”