By Ross Hawkins
BBC News, Trafalgar Square
Things looked slightly stage managed from time to time in Trafalgar Square as mainstream Muslims voiced their anger both at cartoons satirising the Prophet Muhammad, and the extremist demonstrators who had attracted censure in previous protests.
But perhaps that was understandable.
Organisers distributed placards and T-shirts bearing the day's official slogan - "United against Islamophobia, united against incitement".
Home made placards were banned.
The point of the day was, in part, to oppose those who had marched on the Danish embassy with banners calling for executions and chanting: "9/11, we want more."
The last thing the organisers wanted was to recreate that scene.
Stewards and protesters stopped to pray together
One man scrawled a personal message above the official one printed on his banner, then saw stewards moving in to persuade him to hand it over.
He gave in without a fight.
Union flags were allowed.
Several young protesters held a flag in one hand, and a banner in the other.
They were plagued by photographers looking for an image to sum up the day, but they did not seem concerned.
One said: "I'm proud to be Muslim and British.
"This is my identity.
"I'm showing that as a British Muslim I believe in peace and I want to promote peace."
It was not only the flag carriers who met with media attention.
Television crews roamed the square looking for interviewees.
It was clear to those who attended that the world was watching.
The turn out did not match the expectations of some organisers, who anticipated a meeting of tens of thousands of people.
Those who did arrive filled Trafalgar Square, and proved hardy enough to listen to over three hours of speeches on a cold afternoon.
Prayer mats lay in lines on the pavement, as stewards and protesters stopped to pray together.
Ahmed Malik travelled all the way from Manchester.
Home made placards were banned
"Just to come here and see everyone united for the same cause.
"It's a beautiful sight. It's just people from all over Britain who have come together."
There was a mixed reaction to the speakers.
Tahmina Saleem from the Islamic Society of Britain asked the crowd whether placards threatening those responsible for the Muslim caricatures with death represented them.
They responded: "No!"
Others demanded respect, and apologies for the publication of the cartoons.
They warned they would not accept insults being levelled at the Prophet Muhammad.
The independent MP George Galloway was heard by many in respectful silence, but a small group of young men heckled him, shouting questions about his appearance on Big Brother.
As night fell workers dismantled the giant television screen and stage.
Television vans drove away, and the last of the protesters headed back home.
"It's been a brilliant day, a very cold February afternoon," said Ihtisham Hibatullah, one of the organisers.
"One can only hope the extremist element can be marginalised and we can move on."