'Penna' was the German original designation for 'Hindenburg' (ii), the operation to extricate the forces trapped on the Eastern Front in a pocket to the east of the area held by General Christian Hansen’s X Corps of Generalfeldmarschall Ernst Busch’s 16^th Army within Generalfeldmarschall Georg von Küchler’s Heeresgruppe 'Nord' (March/April 1943).