Video report by ITV News correspondent Emma Murphy
Britain fell silent at 11am on Sunday to mark 100 years since the end of World War One.
The Prince of Wales lead the tributes, laying 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.
Ten thousand people took part in a procession past the Cenotaph following the wreath laying.
The Queen, dressed in purple, and Mr Steinmeier watched as flowers were laid at the grave of The Unknown Warrior, later shaking hands at the end of the service.
In Paris, President Donald Trump, Russian President Vladimir Putin and German Chancellor Angela Merkel joined French President Emmanuel Macron and more than 60 other leaders at a ceremony at the Arc de Triomphe a century after the guns fell silent.
Many of the leaders walked side by side along the Champs-Élysées in a somber, rain-soaked line as bells finished tolling. Mr Trump and Mr Putin arrived separately.
The leaders missed the exact moment to commemorate the armistice as they were running late.
In London, crowds began lining up in the Mall in central London from 9am, many wearing poppies and carrying wreaths
Big screens were erected so those waiting could view the Cenotaph service.
Big Ben, which has been silent since renovations to the Elizabeth Tower began in August last year, struck 11 o'clock to mark the hour the Armistice was signed.
The Queen watched the Whitehall service from the balcony of the nearby Foreign and Commonwealth Office.
For the first time, a German leader laid a wreath at the Cenotaph, with President Frank-Walter Steinmeier performing the duty on behalf of his nation in an historic act of reconciliation between the two countries.
Other senior royals including the Duke of Cambridge, the Duke of Sussex and the Princess Royal also paid their respects at the Cenotaph.
The Duchess of Cornwall, the Duchess of Cambridge and the Duchess of Sussex joined the Queen on the balcony.
Prime Minister Theresa May and Labour leader Jeremy Corbyn were also in attendance.
Members of the public who were chosen by ballot for "A Nation's Thank You - The People's Procession" then marched past the Cenotaph.
The portraits, part of filmmaker Danny Boyle’s UK-wide 'Pages of the Sea' project, were then washed away by the tide.
Scottish First Minister Nicola Sturgeon laid a wreath at the Stone of Remembrance in Edinburgh, before attending a service at the city’s St Giles Cathedral.
One of the biggest acts of Remembrance in Northern Ireland took place at the cenotaph at Belfast City Hall.
It was attended by Northern Ireland Secretary Karen Bradley and Ireland's deputy premier Simon Coveney.
Representatives of all the main churches were present, as well as the armed forces and Police Service of Northern Ireland Deputy Chief Constable Stephen Martin.
A cascade of 100,000 poppy petals was released from Cheshire's 50ft high Anderton Boat Lift to commemorate the waterway men of World War One.
The Royal British Legion's petals were released from the Lift near Northwich, known as the 'Cathedral of the Canals', into the River Weaver by member of waterways staff and Canal & River Trust volunteers.
Up to 10,000 people were expected throughout the day at the National Memorial Arboretum in Staffordshire.
Tens of thousands of Australians and New Zealanders gave their lives in the First World War.
The Royal Family stood as thousands of audience members held aloft photos of those who took part in the conflict, and descendants stood in the middle of the hall with pictures of their ancestors.
The Tommies illuminated Marble Arch, Tate Modern, HMS Belfast, Warwick Castle, the Angel of the North, the Tyne Bridge, Titanic Belfast, Cardiff Castle and Edinburgh Castle.