On the 28th of June 1943 German troops launched Case Blue. They dashed towards Voronezh, Stalingrad, and Rostov-on-Don. The insufficiently embattled south sector of the Soviet-German front was breached.
The retreat of the Soviet troops Eastward was going on when a famous order later called “Not a Step Back!” was issued. Special anti-retreat detachments were supposed to stop fleeing military units.