At the heart of the ceremony was the two-minute silence, which began as Big Ben struck 1100.

The silence ended with the firing of a gun from Horseguards Parade by the King's Troop, Royal Horse Artillery, followed by the Last Post sounded by buglers of the Royal Marines.

Nicholas Witchell reports on a Day of Rememberance

The Queen and other members of the Royal Family - the Duke of Edinburgh, Prince Andrew and the Duke of Kent - stepped forward to lay wreaths in memory of the war dead.

They were watched by the Queen Mother, the Princess Royal and her husband Captain Timothy Laurence from a window at the Foreign and Commonwealth Office.

Music of Remembrance

Political figures also joined the service, with Prime Minister Tony Blair, Opposition leader William Hague and Liberal Democrat leader Paddy Ashdown coming together to lay wreaths at the Cenotaph.

They were accompanied by other members of the government and former prime ministers, including Baroness Thatcher, John Major and Edward Heath.

The Queen was the first to lay a wreath in honour of the dead

Ulster Unionist leader David Trimble and Margaret Ewing, Deputy Leader of the Scottish National Party, also laid wreaths on the steps of the Cenotaph, as did Foreign Secretary Robin Cook, who laid a wreath on behalf of the dependent territories.

He was followed by a line of high commissioners representing Commonwealth countries. Almost half a million soldiers from 45 former Commonwealth countries were killed in the two world wars.

Finally the chief of staffs of the three services and the representatives of the Merchant Navy and Fishing Fleets, the Merchant Air Service and the Civilian Services, went to pay their respects.

The Bishop of London conducted a short act of remembrance.

After the ceremony about 10,000 former servicemen and women marched past the Cenotaph.

Honouring the dead

Among those marching were a group of more than 100 veterans of the Falklands War in 1982.

Thousands of war veterans joined the service

It was the first time that they had paraded at Whitehall together as a contingent in their own right.

Also joining the parade for the first time were a group of "Bevan Boys" - national service conscripts who during World War II were ordered to work as miners instead of joining the armed forces.

Hundreds of smaller wreath-laying ceremonies were also taking place at memorials across the country.

In Scotland, hundreds of former servicemen and members of the public gathered for the annual ceremony in George Square, Glasgow.

Following the two minute silence at 1100 GMT, officials laid wreaths at the Stone of Remembrance in memory of the war dead.

The victims of the Omagh bombing were mourned at a Remembrance Day service in the Co Tyrone town.

The names of the 29 people killed by the Real IRA bomb in August were read out by the President of the Omagh branch of the Royal British Legion, Roy Maguire, during a ceremony at the town's college of further education.

The 80th anniversary of the Armistice will also be marked on Wednesday when there will be the annual two-minute silence to commemorate the 11th hour of the 11th day of the 11th month when the guns of World War I fell silent.

The Queen will be in France on that day to attend commemorations in Ypres and Paris.