The Gertrude or Gertrud was the invasion plan for Turkey by Nazi Germany , the idea began forming in the beginning of the summer of 1942 under the secret code-name "Gertrude". This code-name was eventually changed.
According to the documents found in the Ministry for the Occupied Eastern Territories, Nazi leaders knew very well that sooner or later Pan-Turkism would be a danger to Germany if they allowed Turkey and Azerbaijan to join together. This danger of Turkic and Azerbaijani collaboration under a 'Great Turan' in Ankara was actually a perceived threat among Nazi leaders in 1942 and 1943. The idea of Greater Armenia and its realization was a counter-balance to Turkish desires in the Caucasus.
The long yearning of the Armenian people for independence was addressed by the establishment of the Free Caucasus Movement, which had been personally suggested and approved by Adolf Hitler. 
- The Rand McNally Encyclopedia of World War II - Page 54 by John Keegan, Sydney L. Mayer
- Forgotten Legion: Sonderverbande Bergmann in World War II, 1941-1945 by Armin Abramian
- Freiwillige vom Kaukasus. A. Jeloschek, F. Richter, E. Schutte, J. Semler, L. S. Verlag, Graz-Stuttgart, 2003.