The Prince of Wales and Duchess of Cornwall attended a memorial ceremony at the Belgrade New Cemetery as their began their visit of Serbia.
Charles and the president of Serbia, Tomislav Nikolic, lay wreaths at the Memorial Crypt of the Belgrade Defenders.
This was followed by a moment of pause for reflection and Serbian priests read a short prayer.
To mark the occasion, the prince wore an RAF tie, Veterans badge and the shoes issued to him when he joined the RAF in March 1971.
Dressed in a grey and black Bruce Oldfield coat, the duchess stood and observed proceedings as the national anthems of both countries were played by a military band.
The memorial is located above an underground crypt in which the bodies of 4,603 known and unknown soldiers have been laid to rest.
Shortly after the event, the prince and President Nikolic attended a wreath laying ceremony at the Commonwealth War Graves Cemetery.
They were led into the site by a piper from the Royal Irish Regiment, and greeted by a British Military band.
At the conclusion of the ceremony, the prince asked President Nikolic to pause for a short time so he could pay his respects. Following the wreath laying, the last post was played and a short prayer was said.
The cemetery was created to receive the remains of British and Commonwealth casualties brought in from more than 60 small burial grounds and from isolated sites all over the former Yugoslavia.
The burials in the War Cemetery include escaped prisoners of war from Italy and Greece.
The civilians buried here include a mining technician, an English teacher, a newspaper correspondent, a member of the Embassy staff and the child of another member of Embassy staff.
They were buried or re-buried in the cemetery with the permission of the Army Graves Service.