The Nachtigall Battalion (English: Nightingale Battalion), also known as the Ukrainian Nightingale Battalion Group (German: Bataillon Ukrainische Gruppe Nachtigall), or officially as Special Group Nachtigall,[1] was the subunit under command of the German Abwehr special operations unit Lehrregiment "Brandenburg" z.b.V. 800. Along with the Roland Battalion it was one of two military units formed February 25, 1941 by head of the Abwehr Wilhelm Franz Canaris, which sanctioned the creation of the "Ukrainian Legion" under German command. It was composed of volunteer "Ukrainian nationalists," Ukrainians operating under Stephan Bandera's OUN orders.[2]