During the first World War the Ottoman Empire becomes Germany’s ally. Islam becomes an important strategic weapon against France, England and Russia. „Jihad“ – the holy war – becomes a part of German war strategy. In November 1914, Jihad was declared in Constantinople. Muslim soldiers from the British, French and Russian armies were called upon to change sides and to enter the war together with the Ottoman Empire and its German ally against the enemies of Islam. As part of the Jihad strategy, captured Muslim prisoners were interned with Indian and North African soldiers of the French and British armies in special camps. These so called “colonial soldiers” were instigated to uprisings against their colonial rulers. Through the endorsement of their respective religious practices, the soldiers interned in the special camps were induced to defect. On 13th July 1915, the first mosque, for the express purpose of religious practice, was inaugurated on German soil. The mosque was located on the premises of the so-called Halfmoon camp. A special camp for Muslim prisoners-of-war and colonial soldiers. As it occured, that the propaganda was rather successless, the camps however faced a growing interest of scientists. The detained "exotic" prisoners of war became objects of different scientific research projects. One such project was the recording of languages, carried out by the “Royal Prussian Phonographic Commission”. This commission was founded in 1915 and comprised of over 30 scientists from the fields of linguistics, musicology and anthropology. The aim of the commission was to systematically record the different languages and the music of all those interned in the German prisoner of war camps. Under the technical direction of Wilhelm Doegen, 1650 recordings of languages were made. The recordings form the basic stock of the Berlin Sound Archive, today located at the Humboldt-University Berlin. These recordings are the starting point for the project “THE HALFMOON FILES”.