The nation fell silent to remember those who lost their lives in battle on the centenary of the Armistice.
The Prince of Wales led the Royal Family's tributes as the Queen looked on from a nearby balcony at the Cenotaph in London.
The event marks 100 years since the signing of the treaty which ended the battle on the Western Front of the First World War at the 11th hour of the 11th day of the 11th month of 1918.
Charles laid a wreath at the Cenotaph on behalf of his mother for the second year in a row, while an equerry laid a wreath on behalf of the Duke of Edinburgh.
The Queen viewed the service from the balcony of the nearby Foreign and Commonwealth Office, although Prince Philip was absent - one of the few times he has missed the occasion.
He was previously unable to attend in 1956, 1964, 1968 and 1999, a spokeswoman for Buckingham Palace said.
The Monarch was flanked by the Duchess of Cornwall and the Duchess of Cambridge - while the Duchess of Sussex, the Countess of Wessex and Vice Admiral Sir Tim Laurence stood on neighbouring balconies.
The President of Germany, Frank-Walter Steinmeier, also laid a wreath on behalf of the German people.
It is the first time since the Cenotaph was inaugurated in 1920 that a representative of the country has taken part in the UK's national service of remembrance.
President Steinmeier's presence was a symbol of the friendship that exists between the two countries today, a representative of the Department for Digital, Culture, Media and Sport said.
The Duke of Cambridge, the Duke of Sussex, the Duke of York, the Earl of Wessex, the Princess Royal, the Duke of Kent and Prince Michael of Kent all laid tributes to Britain's veterans.
Prime Minister Theresa May and Labour leader Jeremy Corbyn also laid wreaths at the foot of the Whitehall memorial, along with Liberal Democrat leader Sir Vince Cable, Foreign Secretary Jeremy Hunt and Speaker of the House of Commons John Bercow.
The traditional two minutes' silence was held at 11 o'clock and was marked by the chiming of Big Ben - despite the ongoing renovations to the clock tower.
The end of the silence was marked by cannon fire and The Last Post sounded by the Buglers of the Royal Marines before the wreaths were laid.
Scarborough-born Defence Secretary Gavin Williamson said: "To be at the Cenotaph on Remembrance Sunday is a privilege and provides us with the opportunity for reflection along with millions of people in countries that continue to be strong allies.
"The First World War touched communities across the globe and I commend all those who have helped us remember the First World War generation.
"We will never forget them or the sacrifice of thousands of British and Commonwealth troops who have given their lives in other conflicts."
This afternoon, 10,000 members of the public - chosen by ballot - will process past the Cenotaph for "A Nation's Thank You - The People's Procession".
The day will conclude with a Service of Thanksgiving at Westminster Abbey.