The Queen led the nation in honouring the fallen today, as the country fell silent to remember its war dead.
In scenes replicated at memorials across the length and breadth of the United Kingdom and Commonwealth nations, the monarch laid the first wreath at the Cenotaph to commemorate members of the Armed Forces who died fighting in all conflicts since the First World War.
Other senior royals, including Second World War veteran the Duke of Edinburgh and current RAF pilot the Duke of Cambridge - with wife Kate watching from a balcony - joined the monarch and politicians, military leaders, veterans and serving personnel.
Big Ben struck to mark the 11th hour of the 11th day of the 11th month and Whitehall observed a two-minute silence only punctuated by the hum of distant London traffic and birds.
In brilliant autumn sunshine, dignitaries laid wreaths at the Cenotaph before 10,000 veterans marched past to pay their respects to their departed comrades.
The crowds watching the service in central London could be the largest yet, the Royal British Legion said.
The charity's head of remembrance, Helen Hill, said that numbers were swollen as recent conflicts brought the realities of war home to a new generation and created "people who are aged 18-and-a-half who are veterans of recent conflicts".
"Once again the British public has shown its support," she said, adding that the number of veterans marching had increased by 3,000 in the last five years.
"The numbers are going up, not down. There are an increasing number of associations looking after the veteran community. More and more people want to participate in the activities."
The prime minister of the Republic of Ireland laid a wreath at a remembrance service in Northern Ireland today in a historic first.
Taoiseach Enda Kenny attended commemorations in Enniskillen, Co Fermanagh, as the town marked 25 years since the IRA Poppy Day bomb - an attack that claimed 12 lives.
The symbolic visit, which saw Mr Kenny lay a laurel wreath at the town's war memorial, came as the Republic's deputy prime minister, Tanaiste Eamon Gilmore, joined dignitaries at a service in Belfast.
In Scotland, First Minister Alex Salmond joined other public figures to lay a wreath on behalf of the people of Scotland before he attended a Service of Remembrance at St Giles' Cathedral.
He said: "Today presents every man, woman and child in Scotland with the opportunity to pause and reflect on the immense sacrifice which so many have made to protect our way of life and freedom down the years."
In Wales, hundreds of people turned out at Wales' National Service in Cathays Park, Cardiff, in solemn reflection and prayers for peace.
First Minister Carwyn Jones described the service as poignant - and said the thoughts of those attending were replicated at memorials across the country.
The Prince of Wales and Duchess of Cornwall had earlier attended a ceremony in Auckland as part of their Jubilee tour of New Zealand.
Under grey skies the royals sat with New Zealand's prime minister John Key, veterans from across the decades, and members of the public around the Auckland Cenotaph.
The Duke of Kent was also overseas, representing the Queen at a service in the Falkland Islands.
Thousands of people also respected the two-minute silence on Twitter, abstaining from posting messages during the period of reflection.
The idea was spread using the hashtag #2minutesilence.
The National Memorial Arboretum in Alrewas, Staffordshire, hosted an outdoor service of remembrance attended by more than 3,000 people.
The arboretum's focal point, the national Armed Forces Memorial, is designed so that on the 11th hour of the 11th day of the 11th month, a shaft of sunlight dissects its inner and outer walls, falling on a bronze wreath sculpture.
The Portland stone memorial is the nation's tribute to more than 16,000 servicemen and women who have died on duty, or as a result of terrorism, since 1948.
There was also a poignant ceremony in Royal Wootton Bassett, the Wiltshire town honoured by the Queen last year for the way its people regularly turned out to honour the UK's war dead, until the closure of RAF Lyneham.
At the Cenotaph, Corporal of Horse Alistair Grice, from the Blues and Royals Household Cavalry Regiment, said he would be remembering comrades from his unit including Trooper James Munday, who died in an explosion in Afghanistan on October 15 2008 and Lance Corporal Jonathan Woodgate, 26, who was killed on March 26 2010.
The 35-year-old, from Coppull in Lancashire, who saw service in conflicts from Bosnia onwards, said: "It's amazing to see how many people, not just British but foreign as well, who are here to support the British Armed Forces and what we have done in the past.
"What has made it such a special day is that everybody just comes out. If you look at the social websites and the TV and everyone is remembering us."
British troops in Afghanistan marked Remembrance Sunday with a simple ceremony at their headquarters in Lashkar Gah.
Around 150 personnel from the army, navy and Royal Air Force marked the two-minute silence at 11am local time and a bugler sounded The Last Post before a piper from The Royal Dragoon Guards played a traditional lament.
They were joined by coalition representatives from the USA, Denmark, Estonia and Bosnia as well as senior officers from the Afghan National Security Forces (ANSF).