Hosni Mubarak, the Egyptian president, has resigned from his post, handing over power to the armed forces.
Omar Suleiman, the vice-president, announced in a televised address on Friday that the president was "waiving" his office, and had handed over authority to the Supreme Council of the Armed Forces.
Suleiman's short statement was received with a roar of approval and by celebratory chanting and flag-waving from a crowd of hundreds of thousands in Cairo's Tahrir Square, as well as by other pro-democracy campaigners who attending protests across the country.
The top figure in Egypt's new regime is now Field Marshal Mohammed Hussein Tantawi, the country's defence minister.
After the announcement, he drove past Mubarak's former palace, where crowds cheered him. He stopped briefly to thank and hail the pro-democracy campaigners before driving in.
In its third statement to the nation since Thursday, the Supreme Council of the Armed Forces said it was examining the situation "in order to materialise the aspirations of our great nation".
The statement said that "resolutions and statements regarding the ... actions to be followed" in order to achieve the demands of the people will be handed down later.
In the televised address, the spokesman also extended "greetings and appreciation" to Mubarak for his service to the country, and saluted the "marytrs and those who have fallen" during the protests.
'Dream come true'
The crowd in Tahrir responded to Suleiman's statement by chanting "we have brought down the regime", while many were seen crying, cheering and embracing one another.
Mohamed ElBaradei, a leading opposition leader, hailed the moment as being "a dream come true" while speaking to Al Jazeera.
"I can't tell you how every Egyptian feels today," he said. "We have been able to restore our humanity ... to be free and independent".
ElBaradei reiterated that Egypt now needs to return to stability, and proposed that a transition government be put in place for the next year.
The government, he said, would include figures from the army, from the opposition and from other circles.
"We need to go on ... our priority is to make sure the country is restored as a socially cohesive, economically vibrant and ... democratic country," he said.
Ayman Nour, another opposition figure and a former president, told Al Jazeera that he would consider running for the presidency if there was consensus on his candidacy.
He called Friday "the greatest day in Egyptian history".
"This nation has been born again. These people have been born again, and this is a new Egypt."
Amr Moussa, the secretary-general of the Arab league, said on Friday that he would resign from his post, one that he has headed for about ten years, "within weeks". Some analysts say he may well run for the Egyptian presidency when elections are held.
Following Mubarak's announcement, our correspondent in Tahrir Square, said: "Tonight, after all of these weeks of frustration, of violence, of intimidation ... today the people of Egypt undoubtedly [feel they] have been heard, not only by the president, but by people all around the world."
'Explosion of emotion'
Al Jazeera's correspondents across the country reported scenes of jubilation and celebration on the streets of major cities.
"The sense of euphoria is simply indescribable," our correspondent at Mubarak's Heliopolis presidential palace, where at least ten thousand pro-democracy activists had gathered, said.
"I have waited, I have worked all my adult life to see the power of the people come to the fore and show itself. I am speechless," Dina Magdi, a pro-democracy campaigner in Tahrir Square told Al Jazeera.
"The moment is not only about Mubarak stepping down, it is also about people's power to bring about the change that no-one ... thought possible."
In Alexandria, Egypt's second city, our correspondent described an "explosion of emotion". He said that hundreds of thousands were celebrating in the streets.
Responding to the announcement, Barack Obama, the US president, said his country would "continue to be a friend and partner to Egypt", and would provide whatever assistance was "necessary and asked for".
He said voice of the Egyptian people had been heard, and that Mubarak had "responded to the ... people's hunger for change".
He said that moving forward, the Egyptian military must ensure the rights of citizens are protected, that the state of emergency is lifted, the constitution revised and a clear path created to free and fair elections. He also praised the army's conduct so far.
Catherine Ashton, the European Union's foreign policy chief, told Al Jazeera that the 27-nation bloc "respect[ed] the decision that President Mubarak has taken".
She said the EU wanted to "pay tribute to the dignity of" Egyptians' behaviour at this time, and that Europe was ready to offer its assistance in this transition period in the fields of elections, building civil society and other areas.
The Swiss foreign ministry, meanwhile, has confirmed to Al Jazeera that they have frozen assets linked to Mubarak.
Suleiman's announcement came after hundreds of thousands of Egyptians took the streets for the 18th consecutive day, marching on presidential palaces, state television buildings and other government installations.
Pro-democracy activists had dubbed the day 'Farewell Friday', and had called for "millions" to turn out and demand that Mubarak resign.
Hundreds of thousands were seen to have gathered at Cairo's Tahrir Square, which has been the focal point of protests, chanting slogans against the government and expressing their dissatisfaction with Mubarak's statement on Thursday night, when he had reiterated his vow to complete his term.
Hundreds of thousands were also seen demonstrating in Alexandria, where several thousand also marched to a presidential palace there.
Protests were also reported from the cities of Mansoura, Mahalla, Suez, Tanta and Ismailia with thousands in attendance.
Violence was reported in the north Sinai town of el-Arish, where protesters attempted to storm a police station.
At least one person was killed, and 20 wounded in that attack, our correspondent said.
Earlier in the day, protesters had laid siege to the state television's offices in Cairo, accusing the broadcaster of being a Mubarak mouthpiece. The military stood aside and allowed them to surround the building, which had been heavily defended in previous days.
At least ten thousand also gathered outside Mubarak's Heliopolis presidential palace, where our correspondent reported that there was a strong military presence throughout the day, but no indication that the army intended to crack down on protesters.
As crowds grew outside the palace, Mubarak left Cairo on Friday for the Red Sea resort of Sharm al-Shaikh, according to sources who spoke to Al Jazeera.
Earlier on Friday, before Mubarak's resignation, in a statement read out on state television at midday on Friday, the military had announced that it would lift a 30-year-old emergency law but only "as soon as the current circumstances end".
The military said it would also guarantee changes to the constitution as well as a free and fair election, and it called for normal business activity to resume.
Al Jazeera's correspondent in Tahrir Square said people there were hugely disappointed with that army statement, and had vowed to take the protests to "a last and final stage".