In particular, protestors used the march to voice their anger at Prime Minister Tony Blair, and US President George Bush for not calling for a more direct end to the violence in the Middle East.
A small number were arrested as they passed along Whitehall and some threw shoes in the direction of Downing Street.
Organisers thanked all those that had come out for the march, which had been hurriedly organised in just one week. Those behind the rally claimed a great success and asserted that between 80-100,000 took part. However, the official police estimate was 20,000.
Kate Hudson, chair of CND (Campaign for Nuclear Disarmament), said: "It's a marvellous indication of the strength of opposition to the violence in the Middle East. It is a very strong message to Tony Blair to get behind the cause of the ceasefire."
Members of the public, political campaigners and Christian groups from around England, Scotland and Wales were among the crowds that gathered at Speakers' Corner in the London’s Hyde Park.
The marching route saw thousands pass the US embassy in London’s Grosvenor Square.Meanwhile, Saturday also saw a great development in the move to bring about an end to the violence in the Middle East, as France and America, whose opposition on the terms of a ceasefire in the Middle East had been blocking progress at the United Nations, finally overcame their differences.
The two sides said they have agreed on a draft UN resolution to end the fighting between Israel and Hizbollah militants in Lebanon.
Tony Blair welcomed the news as "an absolutely vital first step in bringing this tragic crisis to an end".
The first step towards a ceasefire now appears to have taken place, and many commentators have stated their expectations that a ceasefire could come about within the next week.
However, it is understood that the draft resolution does not include a requirement for an "immediate" cessation of violence, a condition France had previously insisted on. But French representatives said the deal would pave the way for a complete end to the fighting.
