Neubaufahrzeug
The German Neubaufahrzeug series of tank prototypes were a first attempt to create a heavy tank for the Wehrmacht after Adolf Hitler had come to power. Multi-turreted, heavy and slow, they were not considered successful therefore only five were made. These were primarily used for propaganda purposes, though three took part in the Battle of Norway in 1940.
Development
During the 1920s and 1930s, a number of countries experimented with very large, multi-turreted tanks. The British built a single example of the Vickers A1E1 Independent in 1926. This inspired the Soviet T-35, which was built in limited numbers from 1933.
Development of the Neubaufahrzeug (German for "new construction vehicle" - a cover name) started in 1933 when the then Reichswehr gave a contract for the development of a Großtraktor ("heavy tractor") to both Rheinmetall and Krupp. Großtraktor was a codename for the development of a heavy tank, Germany being still forbidden to develop tanks under the terms of the Treaty of Versailles. The technical details of the Vickers A1E1 Independent were then available to the Germans as they were amongst the information sold to them by a British officer, Norman Baillie-Stewart, who acted as a German spy before his arrest in 1933.