Military districts of the Soviet Union

In the Soviet Union, a military district (Russian: вое́нный о́круг, voyenny okrug) was a territorial association of military units, formations, military schools, and various local military administrative establishments known as military commissariats. This territorial division type was utilised in the USSR to provide a more efficient management of army units, their training and other operations activities related to combat readiness.

Source: Wikipedia — Military districts of the Soviet Union (CC BY-SA 4.0)