The Queen has lead events to mark the 70th anniversary of VJ Day, when Japan surrendered and World War Two ended.
She and the Duke of Edinburgh joined the Prime Minister and former prisoners of war at a remembrance service at St Martin's in the Field church in London.
A service was also held in Horse Guards Parade, followed by a flypast and march by veterans of the Far East.
The events remembered the estimated 71,000 British and Commonwealth soldiers who died in the war against Japan, including more than 12,000 prisoners of war who died in Japanese captivity.
Prime Minister David Cameron told the BBC it was important to "honour the memory of those that died, the thousands that died, serving our country, preserving our freedoms".
He said: "I think it's also particularly important perhaps, this anniversary, where so many of the participants are now such a great age.
Japan has also marked the anniversary.
At a memorial service in Tokyo, Japan's Prime Minister Shinzo Abe and Emperor Akihito held a minute's silence.