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 in London's Green Park, Chief of the Air Staff Sir Stephen Dalton said Bomber Command's "service and raw courage" had been recognised.
Some 6,000 veterans and families of the deceased watched a Lancaster bomber drop thousands of poppies in a flypast.
Criticism of large-scale area bombing by the RAF near the end of WWII had 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.
"For their bravery and sacrifice which helped to give us our freedom, we will never forget them."
Doug Radcliffe, secretary of the Bomber Command Association, read an extract from the WWI poem "For the Fallen".
The repetition of the final words, "We will remember them," by all gathered at the ceremony, was followed by a trumpeter playing the "Last Post" while veterans and current service personnel saluted.
The Queen and Duke of Edinburgh departed after the dedication ceremony, leaving the Prince of Wales and Duchess of Cornwall to meet Bomber Command veterans.
The London Ambulance Service later said 24 elderly people at the event were treated and five taken to hospital with dehydration and other heat-related problems.
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 the tone of the work was reflective and portrayed men returning from a mission: "I chose the moment when they get off the aircraft and they've dumped all their heavy kit on to the ground."
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 the memorial "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."
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 specifically 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.
The RAF Benevolent Fund will take over guardianship of the memorial.
A special programme about the ceremony, Bomber Command: A Tribute, is being shown at 17:00 BST on BBC Two on Thursday.