The Queen, the Duke of Edinburgh and the Prince of Wales have attended the dedication of the new national Armed Forces Memorial.
The £6m stone circle in Alrewas, Staffordshire, bears the names of 16,000 service personnel who have died since World War II.
The Archbishop of Canterbury Dr Rowan Williams led prayers at the event.
He said the memorial was about naming the "invisible" ready to risk their lives for the country and world.
There is room for 15,000 more names to be carved on the Portland stone walls of the memorial, at the National Memorial Arboretum.
Vice-Admiral Sir John Dunt, chairman of the Armed Forces Memorial Trustees, opened the ceremony with a speech in which he spoke of the sorrow and pride of the families of the deceased.
He said: "I hope that those who have been bereaved and colleagues of those whose names are engraved find this a fitting place to remember and reflect.
"There will be sorrow for family and friends who come here, but I hope they will also be uplifted and proud - proud that these men and women who paid the ultimate sacrifice have done so by serving their country."
Dr Williams spoke of the importance of memorials.
He said: "All the service and skill that keeps us secure may be invisible a lot of the time, but if we are not to be dishonest, shallow and unreal, we need to make the invisible visible once in a while.
The names of personnel who have died since WWII are listed
"And that's what today is about. Naming all those who have been ready to risk everything for the good of our national community and, indeed, the good of our world.
"Some of them have died in heroic circumstances, some in tragedy and conflict, some in routine duties but all of them as parts of a single, great and generous enterprise."
The royal party was joined at the event by politicians including Prime Minister Gordon Brown.
The memorial, designed by architect Liam O'Connor, honours those killed in combat and training as well as in acts of terrorism.
The ceremony was followed by a flypast of Royal Air Force aircraft from across different decades.
During the consultation period, prior to the memorial's creation, a decision was taken to make it accessible to all communities in the UK, and the central location of Staffordshire was chosen.
The royal party toured the memorial and met the families of service personnel.
'Beautiful and tranquil'
Maureen Norton's brother, Terence Griffin, was on leave from service in Northern Ireland when he was killed by a bomb which exploded on a coach carrying service personnel on the M62 motorway in 1974.
The 54-year-old, from Wigan, Greater Manchester, was introduced to the Queen, Prince Philip, Prince Charles and the Duchess of Cornwall.
She said: "This means an awful lot to me. It means his name has been recognised, along with all the other names.
Prince Philip gave a reading at the ceremony
"Even though I will remember him every day, I can come to this beautiful place. It's so tranquil. I can lay flowers by his name. I feel very proud to be here."
During the tour, the Queen took a moment to examine the name of the Earl Mountbatten, her cousin, who was killed by a Provisional IRA bomb in 1979.
Prince Charles said the people of the UK owed those whose names featured on the memorial "an enormous debt of gratitude".
He said: "The magnificence of this new memorial will, at long last, provide a fitting recognition for all those killed on duty since the end of the Second World War.
"It does not differentiate between those killed in the heat of battle or on a training exercise, by terrorist action or on peace-keeping missions."
The memorial will open to visitors on 29 October.