The Abwehr was a German military intelligence (information gathering) organization which existed from 1920 to 1945. Despite the fact the Treaty of Versailles prohibited the establishment of a German intelligence organization altogether, they formed an espionage group in 1920 within their defence ministry, calling it the Abwehr. With its purpose being defence against foreign espionage - an organizational role which evolved considerably over time. As part of its implied task of counterespionage, the Abwehr gathered both domestic and foreign information, most of it human intelligence in nomenclature. Under General Kurt von Schleicher the individual military service intelligence units were combined and in 1929, placed under his Ministry of Defence, forming the foundation for the more commonly understood manifestation of the Abwehr. Each Abwehr station throughout Germany was based on military (army) districts and more offices were opened in amenable neutral countries and in the occupied territories as the greater Reich expanded. When Hitler replaced the Ministry of War with the OKW and made the organization part of the Führer's personal "working staff" in June 1938, the Abwehr became its intelligence agency and Vice-Admiral Wilhelm Canaris was placed at the head of the organization. Its headquarters (HQ) was located at 76/78 Tirpitzufer, Berlin, adjacent to the offices of the OKW.