The Defence Secretary Philip Hammond has said Britain must never forget the ultimate sacrifice of the 446 servicemen and women who have died in Afghanistan, as the country prepares to pay tribute to those who have died in major conflicts.
Mr Hammond said this year's service in Camp Bastion, in Afghanistan will hold particular significance as it will be the last large-scale act of remembrance in the country before more troops are recalled ahead of the completion of operations at the end of next year.
"As we get closer to the culmination of this 12-year campaign, it is right to reflect upon the sacrifices that have been made by the brave men and women of our Armed Forces, and their significant achievements", he wrote in The Sun on Sunday.
"Four hundred and forty six British servicemen and women have made the ultimate sacrifice in Afghanistan on our behalf, putting their lives on the line to protect us. We should never forget them and we should never forget their families, who are forever without their loved ones."
Mr Hammond also said the dedication, professionalism and courage of Britain's armed forces was "truly the finest in the world".
The provision of military music for the British Army played in the lead up to a two minute silence for Remembrance Sunday, marking the British military servicemen and women who have been killed in action.
The Queen will lead a remembrance service in the capital today as she lays the first wreath on the Cenotaph at Whitehall.
The event is the focal point of the country's Remembrance Sunday ceremonies and will see other senior royals, Prime Minister David Cameron and London Mayor Boris Johnson also leaving floral tributes at the memorial.
After the wreath laying ceremony and two minute silence at 11am, more than 10,000 military veterans and civilians will march past the Cenotaph.
The Queen and the Duke of Edinburgh have arrived at the Royal British Legion Festival of Remembrance as the nation begins three days of honouring those who have lost their lives in conflicts past and present.
The Queen and the Duke of Edinburgh will attend the Royal British Legion Festival of Remembrance tonight as the nation begins three days of honouring fallen soldiers.
Other members of the Royal Family will also be present for the event at the Royal Albert Hall, which will feature performances from pop stars James Blunt - a former army officer - and Katie Melua, plus the tenor Alfie Boe and new group the Poppy Girls.
The audience of 4,000, including Legion supporters and military families, will be joined by an estimated 5.2 million viewers on television.
School children from across the capital are travelling to Belgium today to take part in a special 'Last Post' remembrance ceremony. They will join other children from 62 schools across the UK and royal guests including the Duke of Edinburgh.
The children start their trip in Flanders where they will collect sacred soil from the WWI battlefields, then on Monday they will carry the soil under the Menin Gate memorial as part of the ceremony alongside British and Belgian soldiers.
The soil will eventually come to the UK to form part of the Flanders Fields Memorial Garden which opens at the Wellington Barracks near Buckingham Palace in November 2014, on the centenary of WWI.
Sam Nichols from All Hallows Catholic School told ITV London what it means to him to be a part of the ceremony.