On the second Sunday in November, Remembrance Sunday, members of the Royal Family walk through the Foreign and Commonwealth Office towards the Cenotaph, assembling to the right of the monument to wait for Big Ben to strike 11:00 am, and for the King's Troop, Royal Horse Artillery at Horse Guards Parade, to fire the cannon marking the commencement of the two minutes of silence.
Following this, "Last Post" is sounded by the buglers of the Royal Marines. "The Rouse" is then sounded by the trumpeters of the Royal Air Force, after which wreaths are laid by the Queen and senior members of the Royal Family attending in military uniform. This year, The Queen was followed by Prince Harry, who has served in Afghanistan, representing Prince Charles who was in Canada.
Then, to "Beethoven's Funeral March” wreaths are laid by the British Prime Minister; the leaders of the major political parties from all parts of the United Kingdom; the Commonwealth High Commissioners to London, on behalf of their respective nations; the Foreign Secretary, on behalf of the British Dependencies; the First Sea Lord; the Chief of the General Staff; the Chief of the Air Staff; representatives of the merchant navy and Fishing Fleets and the merchant air service.
Other members of the Royal Family usually watch the service from the balcony of the Foreign Office. The service is generally conducted by the Bishop of London, with a choir from the Chapels Royal, in the presence of representatives of all major faiths in the United Kingdom.
Before the marching commences, the members of the Royal Family and public sing the national anthem before the Royal Delegation lead out after the main service.Members of the Reserve Forces and cadet organisations join in with the marching, alongside volunteers from St John Ambulance, paramedics from the London Ambulance Service, and conflict veterans from World War II, the Falklands, Kosovo, Bosnia, Northern Ireland, other past conflicts, and the ongoing conflicts in Afghanistan and Iraq.
The last three British-resident veterans of World War I, Bill Stone, Henry Allingham, and Harry Patch, attended the 2008 ceremony but all passed away in 2009. After the service, there is a parade of veterans, who also lay wreaths at the foot of the Cenotaph as they pass, and a salute is taken by a member of the Royal Family at Horse Guards Parade. (Source: BBC, Wikepedia)