Demonstrators in Cairo rejoiced Friday upon hearing that President Hosni Mubarak had been toppled after 18 days of protests against his government.

Published: February 11, 2011

CAIRO — An 18-day-old revolt led by the young people of Egypt ousted President Hosni Mubarak on Friday, shattering three decades of political stasis here and overturning the established order of the Arab world.

Shouts of “God is great” erupted from Tahrir Square at twilight as Mr. Mubarak’s vice president and longtime intelligence chief, Omar Suleiman, announced that Mr. Mubarak had passed all authority to a council of military leaders.

Tens of thousands who had bowed down for evening prayers leapt to their feet, bouncing and dancing in joy. “Lift your head high, you’re an Egyptian,” they cried. Revising the tense of the revolution’s rallying cry, they chanted, “The people, at last, have brought down the regime.”

“We can breathe fresh air, we can feel our freedom,” said Gamal Heshamt, a former independent member of Parliament. “After 30 years of absence from the world, Egypt is back.”

Mr. Mubarak, an 82-year-old former air force commander, left without comment for his home by the Red Sea in Sharm el Sheik. His departure overturns, after six decades, the Arab world’s original secular dictatorship. He was toppled by a radically new force in regional politics — a largely secular, nonviolent, youth-led democracy movement that brought Egypt’s liberal and Islamist opposition groups together for the first time under its banner.

One by one the protesters withstood each weapon in the arsenal of the Egyptian autocracy — first the heavily armed riot police, then a ruling party militia and finally the state’s powerful propaganda machine.

Mr. Mubarak’s fall removed a bulwark of American foreign policy in the region. The United States, its Arab allies and Israel are now pondering whether the Egyptian military, which has vowed to hold free elections, will give way to a new era of democratic dynamism or to a perilous lurch into instability or Islamist rule.

The upheaval comes less than a month after a sudden youth revolt in nearby Tunisia toppled another enduring Arab strongman, President Zine el-Abidine Ben Ali. And on Friday night some of the revelers celebrating in the streets of Cairo marched under a Tunisian flag and pointed to the surviving autocracies in Syria, Saudi Arabia, Jordan and Yemen. “We are setting a role model for the dictatorships around us,” said Khalid Shaheen, 39. “Democracy is coming.”

President Obama, in a televised address, praised the Egyptian revolution. “Egyptians have made it clear that nothing less than genuine democracy will carry the day,” he said. “It was the moral force of nonviolence — not terrorism and mindless killing — that bent the arc of history toward justice once more.”

The Muslim Brotherhood, the outlawed Islamist movement that until 18 days ago was considered Egypt’s only viable opposition, said it was merely a supporting player in the revolt.

“We participated with everyone else and did not lead this or raise Islamic slogans so that it can be the revolution of everyone,” said Mohamed Saad el-Katatni, a spokesman for the Brotherhood. “This is a revolution for all Egyptians; there is no room for a single group’s slogans, not the Brotherhood’s or anybody else.”

The Brotherhood, which was slow to follow the lead of its own youth wing into the streets, has said it will not field a candidate for president or seek a parliamentary majority in the expected elections.

The Mubarak era ended without any of the stability and predictability that were the hallmarks of his tenure. Western and Egyptian officials had expected Mr. Mubarak to leave office on Thursday and irrevocably delegate his authority to Vice President Suleiman, finishing the last six months of his term with at least his presidential title intact.

But whether because of pride or stubbornness, Mr. Mubarak instead spoke once again as the unbowed father of the nation, barely alluding to a vague “delegation” of authority.

The resulting disappointment enraged the Egyptian public, sent a million people into the streets of Cairo on Friday morning and put in motion an unceremonious retreat at the behest of the military he had commanded for so long.

“Taking into consideration the difficult circumstances the country is going through, President Mohammed Hosni Mubarak has decided to leave the post of president of the republic and has tasked the Supreme Council of the Armed Forces to manage the state’s affairs,” Mr. Suleiman, grave and ashen, said in a brief televised statement.