Francois Hollande, Angela Merkel and Mahmoud Abbas walk during Charlie Hebdo mass unity rally

They came in their hundreds of thousands: the old and the young; the white, the brown and the black; the left and the right. There were old men in berets; young black people in baseball hats; Jews in yarmulkes; Muslims in headscarves.

 Francois Hollande, Angela Merkel and Mahmoud Abbas walk during a mass unity rally. Photo / AP
About 1.6 million people are estimated to have marched - or in many cases failed to march because the crowds were too densely packed - in the centre of Paris. They marched "for the Republic", "against hatred" and "for history".
A further 2.1 million marched in more than 60 similar demonstrations in towns and cities across France.
They marched to say "I am Charlie" but also "I am Jewish" and "I am a policeman" after three days of terrorist mayhem starting with the massacre at the satirical magazine Charlie Hebdo.

And as if that was not remarkable enough, there was an unprecedented march of the powerful within the "march of the one and a half million". Forty-four world leaders linked arms and walked down the Boulevard Voltaire, pausing for a minute's silence and then again when the names of the 17 victims were broadcast over a loudspeaker.
The victims were listed alphabetically, anarchist cartoonists, Jewish supermarket shoppers and police officers all mixed up together.
Who would have thought that the Israeli Prime Minister, Benjamin Netanyahu, would walk through Paris four places away from Mahmoud Abbas, the President of the Palestinian Authority? Who would have imagined British Prime Minister David Cameron would take part in a street demonstration in the French capital.
"Today, Paris is the capital of the world," said President Francois Hollande. "Our entire country will rise up towards something better."
Many in the crowd also had a sense that something special was happening. France is a land where politics happens on the street but this was something unheard of: a demonstration for the values of the French republic and Western democracy. The last time Paris had seen such a vast and varied crowd on its streets was on the night France won the World Cup in 1998. That was an explosion of spontaneous joy. This was a shout of defiance.
"The whole of Paris seems to be here," said Michel, 46, an estate agent. "I can't describe the mood. There is a feeling of anger and determination but also relief at being able to express our feelings after three days of shock after shock. People will say it's just a passing thing but I think something important is happening here today. France will not be the same after today."
One man stood with an 8-year-old boy displaying a sign handwritten in unusual characters. Asked what it said, he turned the placard around. "It says this - 'Je suis Charlie' - in Kabyle," he said. Kabyle is the minority language of Berbers in Algeria. Hamid said: "I am Kabyle and I am Muslim. The killers were not true Muslims. I am here to say that I support the democratic values of France and I am also a devout Muslim."
The mood of the crowd was a bizarre mixture of sombre, defiant and almost joyous. One sign in the crowd read: "They wanted to bring France to its knees. Instead they brought Europe to its feet." Another said: "Make laugh, not war."
Fifteen minutes before the march was due to begin, the Place de la Republique in eastern Paris was jammed solid.
Most people were unable to move forward. New rivers and streams of humanity still poured into the crowd from every direction. Spontaneously, the people began to clap rhythmically. The clapping spread like a river of sound up every avenue and boulevard.
Just after the scheduled start time, the 44 world leaders emerged from four buses. Cordoned off from the rest of the crowd, they began to move forward arm in arm.
There is no precedent for such a mass turnout of world leaders for anything other than a summit or funeral of a leading monarch or statesman. A little distance away two other marching groups were assembled: first, the relatives and friends and colleagues of the 17 victims; then the leaders of almost every French political party. After 30 minutes, the heads of state and government were shepherded back to cars and buses. Their participation was cut short to reduce their exposure to possible terrorist attack.