As anti-war demonstrations take place around the globe, BBC News talks to some of the protesters who gathered at Parliament Square in London.
Demonstrators gathered in front of the Houses of Parliament
On a bitterly cold Saturday in March, many Britons could perhaps be forgiven if they settled down in front of the fire for a browse through the weekend newspapers and a nice cup of tea.
But thousands chose to leave those comforts behind to vent their frustration at the continuing British military involvement in Iraq.
At Westminster Tube Station, there was little hint of anti-war protests, the only evidence being a painfully polite message on the PA system saying: "Ladies and gentlemen, please use exit number three for the Stop the War march."
In the square, roads were closed, pavements fenced off and march organisers were screaming instructions at the gathering hordes.
The noise of banging drums and piercing whistles filled the air and a light sprinkling of police officers looked on disinterestedly at a thick queue of protesters stretching into the distance.
Among them were self-professed "seasoned campaigners" Anne Lemon, 46, and 44-year-old Peter McGahan who had travelled from Bristol to join the march.
Dawn Clarke made sure the sound of drums was heard
Ms Lemon, a schoolteacher, said the ongoing "occupation" of Iraq was an "insult to the Iraqi people".
"Britain should leave Iraq now, and they should leave enough money behind for the country to be properly reconstructed by Iraqi people," she said.
Mr McGahan and Ms Lemon were among many of the protesters who also marched against the Iraq war in 2003.
They denied that anti-war protests had failed, saying the march was one of many which continued to show how isolated leaders such as Prime Minister Tony Blair have become.
Another veteran of 2003 campaign was Dawn Clarke, from the Barking Bateria marching band - she was taking responsibility for the booming bass drum.
Alan Maccormac said all wars should be stopped
She said there was "no chance" Western political leaders would change their minds over Iraq "but that doesn't mean we've got to give up".
"Who are they to decide how to run any other country? Would Blair or Bush accept it if Iran decided it didn't like the way we were doing things and invaded us?"
As with many large-scale protests, Iraq was not the only issue on the agenda. All around Ms Clarke there were bewildering numbers of banners exhorting people to "Boycott Israel" or "Free Palestine" or even take part in "World Revolution".
More familiar placards proclaiming Mr Blair and US President George W Bush to be murderers were seen in their thousands, brandished by people representing organisations from students' unions and socialist parties to African liberation groups and even Hare Krishnas.
Anne Lemon and Peter McGahan travelled from Bristol to protest
Alan Maccormac, who described himself as "old enough to remember the Cuban missile crisis", said the point was simply that "there should be no wars at all".
"Unless people show their feelings in public - united, forming a bigger force - the government is not going to know how they feel," he said.
Many of those at Parliament Square expressed a similar sentiment - they just wanted to register their opposition to Iraq in particular, and wars in general.
Who knows what effect it will have but, as one marcher pointed out, "it's got to be more effective than sitting at home in front of the tele". And considerably colder, too.