Danubia

Danubia refers to a loosely defined region that roughly coincides with the Danube river basin in Central and Eastern Europe. It stretches from the Black Forest of Germany in the west to the Black Sea in the east, covering parts of twenty countries. Historically, Danubia had been owned by the Austro-Hungarian Empire (Until 1918). Now it is split among Austria, Slovakia, Hungary, Czech Republic, Poland, Ukraine, Italy, Slovenia, Serbia, Bulgaria, Croatia, Bosnia Herzegovina and Romania.

Military science
"Danubia" was the name given to the Opposing Force at the Combat Maneuver Training Center at Hohenfels, Bavaria. It represented assorted Warsaw Pact forces that American and allied forces might encounter.