A £6m memorial to the 55,573 airmen of Bomber Command who died during World War II has been unveiled by the Queen.
At the ceremony, Chief of the Air Staff Sir Stephen Dalton said the "service and raw courage" of those who died and surviving veterans had been recognised.
Some 6,000 veterans and families of the deceased watched a Lancaster Bomber drop thousands of poppies in a flypast.
Criticism by some of large-scale area bombing by the RAF near the end of WWII stalled plans for a memorial for years.
Veterans from Australia, New Zealand, Canada and other countries who served alongside the British crew also attended the ceremony.
Air Chief Marshal Dalton said: "Many of those who gave us our freedom, and to whom this memorial is dedicated, cannot join us physically, but their spirit is certainly here.
"With the building and unveiling of this magnificent memorial, they will now know that this country and the Commonwealth have shown them and the remaining veterans that their service and their raw courage has been recognised. It is also true that their dedication to doing their duty has truly been acknowledged.
"For their bravery and sacrifice which helped to give us our freedom, we will never forget them. Indeed, we will remember them."
'All nations' honoured
The memorial, designed by Liam O'Connor and built in Portland stone, features a bronze 9ft-high sculpture of seven aircrew.
Sculptor Philip Jackson said his work was intended to be reflective and so portrayed the men after they had returned from a mission.
"I chose the moment when they get off the aircraft and they've dumped all their heavy kit onto the ground, and they're looking back and looking for their comrades."
The memorial also has a roof made of aluminium reclaimed from a Handley Page Halifax III bomber shot down over Belgium in May 1944.
An inscription says it "also commemorates those of all nations who lost their lives in the bombing of 1939-1945".
Pilot Alan Biffen, 87, said: "I am so glad that at long last Bomber Command is being remembered not only for what it achieved but also for the lives of the young men who never came back.
"Many of them were boys. I myself added a year to my age at 16 so that I could join the air force."
Almost half of the 125,000 men of Bomber Command died, many killed by night fighters and anti-aircraft fire in raids over occupied Europe.
The ceremony is the culmination of a five-year campaign, spearheaded by the late Bee Gees singer Robin Gibb.
The Bomber Command Memorial Appeal secured funding from public donations and private donors John Caudwell, Lord Ashcroft and Richard Desmond.
There were no campaign medals for Bomber Command after the war and no mention of it in Prime Minister Winston Churchill's victory speech.
It was criticised by some for raids on Dresden in the closing months of the war, causing fire-storms which killed about 25,000 civilians in the destruction of the city centre.
Speaking at Green Park ahead of the dedication ceremony, Bomber Command veteran Cecil Hayley agreed the memorial was about reconciliation as well as remembrance.
"I sometimes look back in horror to think what I was required to do. But, it was what we were trying to do ... it was part of the task of finishing the war and I console myself that this is what we had to do."
Bomber Command Association chairman Malcolm White said it was clear that the memorial's message included a sense of reconciliation.
"That's why it's writ large on the wall, 'We remember those of all countries who died in 39-45,'" he said.
He said he had been in touch with the mayor of Dresden and spoken to media in the German city as part of the project.
Councillor Alastair Moss defended Westminster Council's decision to grant planning permission to the memorial, saying it "reflects what the majority of today's public want to say about bravery, sacrifice and suffering."
The RAF Benevolent Fund will take over guardianship of the memorial.
A special programme about today's ceremony, Bomber Command: A Tribute, is being shown at 17:00 BST on BBC Two on Thursday.