Millions of Britons have held a two-minute silence to remember the nation's war dead.
The tribute started at 11am, the time the guns on the Western Front fell silent at the end of the First World War in 1918.
Ceremonies nationwide commemorated fallen servicemen and women from both World Wars and later conflicts, including the 385 British personnel who have died since operations began in Afghanistan in 2001.
The silence was particularly poignant for those at Camp Bastion in Afghanistan, who are mourning the loss of the latest soldier to die on active service.
Private Matthew Thornton, 28, from the 4th Battalion The Yorkshire Regiment, was killed by an IED while on patrol in Babaji on Wednesday.
His family paid tribute to him last night as a "dedicated soldier" who "loved life".
In a recorded message used at the Royal British Legion ceremony in Trafalgar Square, Prime Minister David Cameron said: "We stand together to honour the incredible courage and sacrifice of generations of British servicemen and women who have given their lives to protect the freedoms that we enjoy today.
"From the trenches of the First World War to the desert of Afghanistan, our Armed Forces have proved time and again that they are the bravest of the brave and the very best of what it means to be British.
"We can never fully repay the debt we owe them."
He added: "While we're in the park, at the cinema or watching the football, our servicemen and women are out there, day and night, fighting in the heat and dust, putting their lives on the line for us.
"That's the true character of the British Armed Forces - the Army, Royal Air Force and the Royal Navy - of which we are so incredibly proud.
"So today we stop to say thank you, and to remember those who are no longer with us but whose sacrifice and valour will be honoured long after we are gone."
Deputy Prime Minister Nick Clegg said: "Right now, British troops are stationed across the globe - in places as different as Afghanistan, the Falkland Islands, the Caribbean, the Horn of Africa, central Europe and the Mediterranean - fighting terrorism, keeping the peace, delivering aid, defending vital shipping lanes, tackling the scourge of drugs. They do it without fanfare. They don't expect thanks. They just get on with the job, and the world is safer for it.
"Our service personnel follow in the footsteps of great men and women and they are a credit to their memory. Today let me take this opportunity to thank them for it - they are at the heart of what makes this country so great."
War memorials in the UK's villages, towns and cities became the focal point for remembrance at the "11th hour of the 11th day of the 11th month" - the time the peace agreement between Germany and the Allies took effect in 1918 after four years of fighting.
Wreaths were laid at the Cenotaph in central London during a remembrance service organised by the Western Front Association.
Brother Nigel Cave, the association's padre, led the ceremony which was attended by senior defence staff along with servicemen and women.
At the National Memorial Arboretum in Staffordshire, a service of remembrance was attended by local and national dignitaries.
The Armed Forces Memorial is designed so that at 11am on November 11 a shaft of sunlight passes though a slot in its inner and outer walls and hits a central bronze wreath sculpture.
Television stars paid their own tribute to Britain's fallen at an event in Trafalgar Square which featured musical performances and readings.
Among the performers were Downton Abbey actor Dan Stevens - whose role in the period drama saw him in the trenches - Strictly Come Dancing's Vincent Simone and Flavia Cacace, singing trio The Soldiers and soprano starlet Laura Wright.
The Archbishop of Canterbury, Dr Rowan Williams, visited the Royal Naval Air Station at Yeovilton, Somerset, to take part in the Act of Remembrance at the Royal Naval Cemetery at St Bartholomew's Church.
Meanwhile, representatives of animal charities gathered at the Animals In War Memorial in London's Park Lane to remember the role of animals in conflict.
Many schoolchildren across the nation also observed the two-minute silence.