It started when tens of thousands of people flowed into Tahrir Square on Friday – a day they called the 'Friday of Correcting the Path of the Revolution'.
Delegations came from across the country with their local flags and banners. The peasants' union, representing up to 30,000 of Egypt's poorest farmers and rural workers, was there in force.
Huge contingents of organised football fans from the biggest Cairo teams joined the demonstration too. Rival fans from Zamalek and Ahly had called a truce for the day in order to protest in Tahrir together.
The demands of the protest were wide-ranging, bringing together the democratic and social struggles, including an end to military trials and a living wage for workers.
'The people are the red line you cannot cross,' shouted the demonstrators to Marshal Tantawi and his colleagues on the Supreme Council of Armed Forces. 'Down with military rule!'
Hours before the protest started, the generals recognised that the numbers would be too great for them to keep Tahrir Square under police occupation, as it has been since the beginning of August.
The riot squad and military police vanished, leaving the square in the hands of the people once again.
The energy and enthusiasm of the protesters spilled out down the narrow side streets in marches of thousands on the interior ministry, the high court and the state TV building.
Then 4,000 marched from Tahrir to the Israeli embassy in Giza – and tore down the wall which was erected only last week to keep demonstrators out.
A socialist activist who was with them told me, 'There were a few police at the entrance, but they withdrew when the crowd got too big. Four young guys climbed up the outside of the building to take down the flag.
'They got into the embassy from the top, and others stormed in the building from the bottom. They found a lot of historic documents from the embassy archives and threw them out to people below.
'The army is frightened of the depth of popular anger, so they tried to avoid a direct confrontation when they realized the scale of the protests. Some people are saying that the whole thing is a conspiracy by the army, but I feel sure that they would not voluntarily put themselves in this position.
'Anger against Israel is already very high – and it will rise further if the UN recognition of a Palestinian state is vetoed by America.'
The protest marks an important shift in the balance of forces on the streets. This is the first time demonstrators have returned to Tahrir in large numbers since the sit-in was violently broken up on 1 August.
The scale of the demonstration, despite the Muslim Brotherhood leadership's boycott, was also important. It shows that despite their huge presence in Tahrir Square on 29 July, Islamist forces are by no means dominant in the streets.
Yet it is in the workplaces that the most important gains are being made at the moment. Government ministers have been kept busy meeting workers all week.
The Mahalla textile workers' demands were met before their walkout started.
Postal workers have been on strike across much of the country and teachers are expected to strike on Saturday.
They are likely to be followed by hundreds and thousands of others, eager to win the same gains as the Mahalla workers and the powerful Cairo bus workers' union.
Full report and analysis in this week's Socialist Worker