I have never experienced a march quite like this one. The sheer number of people massed in the streets around the Place de la République made it impossible to move after a certain point. I gave up trying to reach my group of English journalists at the planned rendezvous and stayed motionless for nearly two hours, packed shoulder to shoulder with another group of journalists who had come by coach from Belgium and were bound for the same meeting point 200 metres away.

Apart from the Belgians, I seemed to be the only non-French person there. But the French around me came in all colours, sizes, religions and age groups. Most had placards saying ‘Je suis Charlie’ and some read ‘Je suis flic (cop), je suis juif, je suis la République’. Many had tricolours, ready to be waved, and larger flags hung from the balconies and windows over our heads, whose occupants were leaning out. The mood was good-humoured and, above all, expectant.

From time to time a rumour would sweep the crowd that we were finally about to move and applause rang out, only to die down as it became obvious that we weren’t going anywhere. One of the Belgians gallantly held a placard over my head during a brief shower. Looking up, I noticed a police sniper on the roof of the building opposite and a man who had wrapped himself around a traffic light acted as a lookout for all of us, but with nothing to report. Finally, we were reduced to watching tv coverage of François Hollande and other leaders in the Place on another man’s Iphone, which he held up to be seen by the people pressed around him.

When we finally did start to move, it was with no warning at all and at a slow shuffle. I fished out the pencil I had brought as a symbol of freedom of expression and held it up, although it was dwarfed by some of the giant cardboard pencils being waved around me. Some people started to sing the ‘Marseillaise’, soon drowned out by louder chants of ‘Char- lie, Char- lie’, although many people were silent. The relief of being able to move was inexpressible. In fact, so much so that I broke through the solid mass of people in the Boulevard Voltaire onto the pavement and then into a side street, cravenly abandoning the Belgians and the official route.

All around me people were doing the same, spilling out into the streets nearby, large and small, without in any way diminishing the size of the official march. It looked as if the whole of Paris had taken to every street in the city, holding ‘Je suis Charlie’ signs. I passed a tempting pavement café where people were clinking glasses and saying ‘Vive la France!’ but didn’t stop walking until I reached my local café on the Ile St Louis, from where I rang my neighbour on the off-chance that she would be free. Luckily, she too had abandoned the official route and was walking home. With a sigh of relief she sank into a chair and we drank a toast to the Republic.

As a complete stranger said to me, when I confided to him that I was slipping away, ‘Ce n’est pas grave, l’important, c’était d’être là’: That doesn’t matter, the main thing is that you were here.