Tonight marks the 80th anniversary of a remarkable wartime story of courage, ingenuity and determination, when in 1941, a group of Polish Home Army parachutists, all volunteers, were dropped behind enemy lines into occupied Poland to begin the fight back for their homeland. Now English Heritage is calling for those with family connections to or memories of the Cichociemni at Audley End to share their stories.

This elite group of special operations paratroopers, trained in covert operations, sabotage and intelligence-gathering would go on to become the pride of the Polish Republic, and many undertook their final stage of training at Audley End House in Essex, now in the care of the charity. A memorial to the Cichociemni stands proudly in the grounds, commemorating their achievements and sacrifices.

A scrap of graffiti in the coal gallery candle store, torn labels in the cellar where guns and ammunition were stored, the remnants of a timetable in the former briefing room, nails in bedroom walls where pictures of home were hung and insulators for telephone wires still stuck in trunks of trees are the only visible signs that the Silent Unseen ever inhabited this Jacobean stately home, where 527 completed the rigorous final stage of training before deployment.

Arkady Rzegocki, Polish Ambassador to the UK, said: "The 80th anniversary of the first mission of the Silent Unseen – Cichociemni is an important date in the history of Poland, Polish special operations forces and Polish-British relations. On the night of 15-16 February 1941, the first group of Polish Home Army parachutists, who were all volunteers, were dropped into occupied Poland, the first such airdrop behind German lines, offering a glimmer of hope to the besieged homeland that help was coming. With skills they developed in such places as Audley End, home to the Polish section of the Special Operations Executive, Cichociemni landed under cover of darkness to support the fight against the enemy, becoming the pride of the Polish Republic. Their brave and heroic service inspired GROM, one of Poland's premier special missions units, to adopt their name and continue their traditions. Let their name and sacrifice never be forgotten. Thank you to all who keep the memory of Cichociemni alive."

Andrew Hann, English Heritage Historian, said: "It is a privilege to play a small part as a caretaker of this incredible story where individuals acted so selflessly to risk everything in the defence of their homeland against Nazi occupation. We are honoured that Audley End has come to hold such as special place for Poles as the spiritual home of wartime resistance and we’re committed to helping share that story in the hope that the sacrifices of these extraordinary people go on to inspire future generations.

He continues: "We’d love to hear from the public who have a connection or story to share about the Cichociemni at Audley. We’re particularly interested in hearing from those in the local area at the time, who may remember hearing bangs in the night, or seeing troops crossing fields in the darkness. Perhaps unsurprisingly, given that they were highly trained to be both 'silent and unseen' they left little obvious trace."