For prisoners held at concentration camps during World War II, a new language called lagerszpracha arose from necessity. In many camps, there were prisoners of up to forty different nationalities, many of whom spoke different languages. It became increasingly apparent that they would need to use a more familiar common language (also known as a lingua franca to us word nerds).
This language became lagerszpracha, also refereed to as lagerjargon or, rather morbidly, crematorium Esperanto. The official language of the camps was still German, but prisoners used lagerszpracha to communicate among themselves, particularly because using their native language was forbidden.
There were different varieties of lagerszpracha, which was created primarily out of Polish, Yiddish, Hungarian and Silesian dialects, as well as other languages spoken in the given camp. These differences were observed not only between camps but also between the language used in men’s and women’s camps.
Below is a book I am currently reading, which briefly mentioned lagerzspracha and made me curious to investigate more: