Operation Barbarossa  Hitler's Directive 21

On 22 June, a door opened before us, and we didn't know
what was behind it... the heavy uncertainly took me by
the throat.      Adolf Hiltler.

The greatest land war in recorded history began at 3.30 a.m. on 22 June 1941,
the day after the 129th anniversary of Napoleon's attack on Russia in 1842.
The initial German front was 995 miles-1600 km long, and there was another 620 miles-
992 km along the Finnish border. The main front would soon expand to 1490 miles-
2384 km and extend to a depth of over 600 miles-960 km. In to this great space of
steppe, forest and swamp marched the best of the German Army, amounting to
threequarters of it's field strength. By the end of the year, 3.500.000 Red Army soldiers
were in captivity and 4.000.000 had died in battle. At one time the Germans occupied
some 900.000 square miles-1.440.000 square km of Soviet territory.

The road to Stalingrad - Army Group South

22 June 1941 - Operation Barbarossa : Germany attacked the Soviet Union :
Three Army Groups  with 123 divisions, including 17 panzer divisions and 35 divisions
of the allied nations. 3350 tanks, 7.000 field guns and 2000 Luftwaffe aircraft.

Army Group North, Army Group Center and Army Group South. (o.o.b. below)
Army Group South was commanded by Gerd von Rundstedt. (biography below)
 

Gerd von Rundstedt.
Commander Army Group South.

The main objectives were :

- Leningrad (Army Group North).
- Moscow (Army Group Centre).
- Rostov (Army Group South).

Map of operation Barbarossa

By 31 July 1941 the Germans had suffered 213.301 casualties, around fifteen
per cent of their total invasion force and had lost 863 tanks through enemy
action or breakdown beyond repair, nearly one quarter of the original number.
 

Order of battle Army Group South commanded by Gerd von Rundstedt
(soon supported on his right by a small Hungarian and two Romanian Armies)

11th Army : General Ritter von Schobert