The Royal Air Force has led commemorations for the 75th anniversary of the Great Escape.
In 1944, 76 prisoners of war attempted to escape from a Nazi camp through tunnels they had painstakingly dug underground at Stalag Luft III.
Only three of the men managed to escape to safety, while 50 of the 73 who were recaptured were killed.
Many internees at the PoW camp were British airmen and the RAF took part in a flypast and formed a guard of honour alongside the Polish Air Force as part of the commemorations in Poland on Sunday.
Defence Secretary Gavin Williamson said: “Today marks 75 years since our prisoners of war performed one of the greatest and most complex escape operations of all time.
“We must never forget that in the fight for freedom, and in the hopes of liberating themselves and their comrades, 50 courageous lives were lost.
“Their bravery is a testament to the camaraderie and strength of the RAF, who worked tirelessly to liberate Europe from Nazi occupation.
“Sadly, we are slowly losing our heroes of the Second World War, so it is more important than ever that we preserve their legacies by continuing to tell their stories.”
Chief of the Air Staff, Air Chief Marshal Sir Stephen Hillier, joined Air Commodore Charles Clarke, a PoW who was held at Stalag Luft III at the time of the escape, in a ceremony on the site of the camp which at the time was in Germany, but is now in Poland.
Relatives of those who escaped and Government representatives were also present at the commemorations, which included a remembrance service at Poznan Old Garrison Cemetery, where 48 of those executed are buried.
The story of the Great Escape heroes, who gave their three tunnels the code names Tom, Dick and Harry, gained even more prominence in 1963 when it became the basis for a Hollywood film of the same name starring Steve McQueen and Richard Attenborough.
A special screening by the RAF Benevolent Fund will be part of a commemorative event, The Great Escape With Dan Snow, hosted by the TV historian, which will be streamed to cinemas across the UK.
Last month Dick Churchill, the last surviving member of the 76-strong group who made it out of the camp, died aged 99.
The former squadron leader, who lived in Crediton, Devon, was one of the 73 recaptured by the Germans within three days of the breakout after Hitler became aware and ordered locals to search their land and buildings.
Earlier this month Second World War pilot Jack Lyon, who was in the Stalag Luft III camp after his bomber plane was struck by flak near Dusseldorf, died aged 101.
Mr Lyon, who was a flight lieutenant, was recruited by other prisoners to carry out surveillance of the compound, but the plot was discovered before he could make his own escape.