The RHS Lindley Library has uncovered the story of the group of British men who set up a horticultural society in the Ruhleben civilian detention camp in Germany during the Great War.
More than 5,000 British citizens were interned at Ruhleben, an old racecourse outside Berlin, which was described when it opened as "scandalously inadequate" and "not fit to keep pigs in".
Working together they transformed the camp, overcoming terrible conditions and battling hopelessness to create a self-governing society within its fences.
Now the society is planning an exhibition, this October to commemorate their story, and the centenary of the First World War.
The Ruhleben Horticultural Society was formed early on and within days of its first meeting, the secretary wrote to the RHS asking to become an affiliated society.
The RHS responded at once, sending huge amounts of seeds, bulbs and advice to its new affiliate, deep behind enemy lines. The members of the new society, eventually numbering more than 900, fed the camp's inmates, earned money to fuel its fledgling economy, disguised their bleak surroundings and organised RHS-standard flower shows to boost morale.
The two societies corresponded throughout the war, with internees sending back the photographs, letters and reports which will make up most of the exhibition.
RHS head of libraries and exhibitions Fiona Davison said: "The story of the Ruhleben Horticultural Society is completely unique, in that unlike many First World War histories that tell of the triumph of the human spirit over adversity, it is all but unknown.
"We have a fantastic collection to work with but there is still much that can be added to the Ruhleben story and we hope very much to hear from members of the public who can help us with this.
"One of the aims of the projects being undertaken around the centenary of the First World War is to help us as a society better understand, connect with and remember the lives and experiences of those affected by the war. The history of the Ruhleben internees is an as yet unexplored part of this experience and it is a privilege for us to help in the telling of it."
The RHS is asking anyone who thinks a relative may have been one of the internees to get in touch at email@example.com and share their knowledge of the prisoner horticulturalists.
Click here to see photographs of the internees.