Queen Elizabeth will pay tribute to the British armed forces in her annual Christmas Day message on Friday after the bloodiest year for British and American troops in Afghanistan since the 2001 US-led invasion.
The queen, who is the titular head of the military, spoke earlier this year of the nation's "deep and enduring gratitude" to the armed forces.
With British troops deployed in more than 80 countries, including around 10,000 in Afghanistan, she will use her traditional message to thank them for their service, according to brief details released by royal officials today.
The number of British troops killed in Afghanistan this year reached 100 in early December. The Defence Ministry said the two latest soldiers to die, earlier this week, may have been shot by mistake by their comrades.
After the invasion of Iraq in 2003, the queen broke with tradition by filming her message in the cavalry barracks in Windsor, rather than inside Windsor Castle, Buckingham Palace or her Sandringham estate in Norfolk.
Unlike the Queen's Speech at the annual opening of parliament, the monarch expresses her own views rather than those of the government in her Christmas message.
"It is an opportunity to speak directly to the public, to react to their concerns and to thank and reassure them," the royal website says.
The queen has made a Christmas broadcast in every year but one since her 1953 coronation. There was no message in 1969 because of the media exposure already generated by the investiture of her eldest son and heir, Charles, as Prince of Wales and a TV documentary about the royal family.
Channel 4 will broadcast an alternative Christmas message from former television presenter Katie Piper, who suffered horrific burns after an ex-boyfriend arranged for acid to be thrown in her face in March 2008.
She will urge viewers to "appreciate the beautiful things and the beautiful people that you have in your life".
The queen's 57th message, pre-recorded in Buckingham Palace, will be shown at 1500 GMT on BBC1, ITV and on the video-sharing website YouTube, www.youtube.com/user/TheRoyalChannel.