Aufbau Ost (German: Buildup in the East) was the German operational code name for the mobilisation of forces before the start of Operation Barbarossa and the subsequent invasion of the Soviet Union.
On 8 August 1940 Hitler ordered Walter Warlimont, Deputy Chief of Alfred Jodl, to determine the positions of Soviet troops in the East. The appropriate directive was signed the next day by Wilhelm Keitel. It stated that due to the threat of British air attack on Eastern Germany it was necessary to use the eastern territories for drawing and preparing the new units. In compliance with the directive, the building organization of Fritz Todt started equipping the battleground while the rear organs managed the logistical support in the East. Meanwhile, preparations for adjusting the Soviet rail gauge to match the Western European were taking place.
Aufbau Ost (German for: [re-]building [up] the East) may refer to:
Aufbau Ost (1940), a Nazi military plan;
"Aufbau Ost", a term for the economic challenge which Germany faced after its 1990 reunification.List of Axis operational codenames in the European Theatre
The list of Axis named operations in the European Theatre represents those military operations that received a codename, predominantly from the Wehrmacht commands. It does not represent all operations that were carried out by the Axis powers, or their allies in the European Theatre during the Second World War. Although named operations, the entries represent activities that spanned the entire theatre or large parts of it, multi-year campaigns, battles, engagements and even combat that resulted in relatively small actions by armed forces.