Britain's Royal Air Force will lead commemorations of 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 will take part in a flypast and form a guard of honour alongside the Polish Air Force as part of the commemorations in Poland.
Defence Secretary Gavin Williamson paid tribute to the PoW escapees.
"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."
Chief of the Air Staff, Air Chief Marshal Sir Stephen Hillier, will join 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 will also be present at the commemorations, which include 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.
Last month Dick Churchill, the last surviving member of the 76-strong group who made it out of the camp, died aged 99.
Australian Associated Press
