The Gertrude or Gertrud was the code name of the joint invasion plan for Turkey by Nazi Germany and Kingdom of Bulgaria, during Case Blue.[1]
The Gertrud was scheduled to begin in late 1941 and would be completed in five weeks. Initially, four infantry divisions were to be brought in from Denmark, all supported by an artillery brigade. This army would lead the attack from northern Turkey, leading the invasion. The Kriegsmarine would support the army with twenty-seven ships stationed in the Aegean Sea and the Dodecanese.[2]
However, the project was abandoned because of the rapid advance of the Red Army in the Caucasus region, the conclusion of the German–Turkish Treaty of Friendship, and the Allied invasion of Sicily.[3]