During the Battle of Britain, how prepared was the East Front?

Question

The Battle of Britain went on between July and October of 1940. During this time, how prepared was the German Eastern Front?

Specifically, how much of the German Army was on the West (either occupying France or waiting to invade Britain), versus how much guarding the East? How much of the Luftwaffe was busy with Britain, versus how much was guarding the East? Was the East Front fortified at all with trenches?

Or perhaps, was the east guard given mostly to the Italians?

BTW, at this time the Axis did not include Hungary, Romania, Yugoslavia, or Bulgaria. So the Eastern Front is relatively small at this point, running through Poland, and along Austria and Italy.

Edit: Another way of going about this is, how much of the Wermacht was occupying West Poland and Czechoslovakia at this time?

Answer 1

There wasn't much defending Germany and the East at all. From what I can tell, most of Germany's air power was dedicated to the Battle of Britain, and most of the army was recovering from the Battle of France in France.

I can cover the air units in the most detail. Germany threw 80% of its air power at Britain, about 3,350 aircraft out of 4,000 (not all servicable).

At the time, Germany had 5 Luftflotte, high level organizations responsible for a particular region. 2 (Belgium), 3 (France), and 5 (Norway) were dedicated to attacking Britain. Luftflotte 1 (Berlin) and 4 (Vienna) were stripped of nearly all their attack (Fliegerkorps) and fighter (Jagdfliegerführer) units to support the battle.

This is not to say there was nothing defending Germany. These were just the high level units. The Germans were masters of reorganization. The smaller units, the Jagdgeschwader (JG), would still be operating around Germany. For a detailed listing, here's an exhaustive list of Luftwaffe air units and their bases by date. If you go through them all, please feel free to edit this answer with the info.

References

• World War II Armed Forces — Orders of Battle and Organizations — Operation Sea Lion
• The Luftwaffe, 1933-1945

Answer 2

Around the time you ask the only active German armies on the east were the XI (created around October 1940) and XVIII army. While armies I, II, IV, VI, VII, IX, XII and XVI where in France, plus both Panzer armies. An army was in Norway as well. Obviously the size and quality of each army was quite variable and surely some units of occupation were not under the command of an army.

So we might say that only a 15% of the army was in the east during the Battle of Britain.

Poland didn't have any kind of fortification and no Italian troops were in the east by then. In fact, Italians didn't know about the attack to the Soviet Union.