On the 18th September the defenders of Leningrad saw the tanks of the German 4th Panzer Group being loaded on to trains, to be transported to the Moscow front. It was the first clear sign that there was not going to be a direct assault on the city.

The bombing that was taking place was not something preparatory to an attack - it was the strategy.

‘Petersburg — the poisonous nest from which, for so long, Asiatic venom has spewed forth into the Baltic — must vanish from the earth's surface.’

Leningrad, almost completely encircled on the 8th September, would be besieged and bombed not in an attempt to make the city surrender but in order to kill the people within it.

Hitler would soon issue a War Directive spelling out the the policy but he had already told Otto Abetz, the German ambassador to Vichy France on the 16th

Petersburg — the poisonous nest from which, for so long, Asiatic venom has spewed forth into the Baltic — must vanish from the earth's surface. The city is already cut off. It only remains for us to bomb and bombard it, destroy its sources of water and power and then deny the population everything it needs to survive.

One of the first Luftwaffe bombing objectives had been the food warehouses for the city - centralised under the Soviet system. The rations for civilians had now been reduced. Much worse was to come.

The Wehrmacht High Command had asked Professor Ernst Ziegelmeyer of the Munich Institute of Nutrition to calculate how long it would take to starve the entire Leningrad population. Based on the census figures, the expected winter temperatures and the likely availability of food he thought they should maintain the siege throughout the winter:

It is not worth risking the lives of our troops. The Leningraders will die anyway. It is essential not to let a single person through the front line. The more of them stay there, the sooner they will die, and then we will enter the city without trouble, without losing a single German soldier.

At first it was proposed to surround the city with an electrified fence and machine guns but there was a fear that epidemics within the city would spread to German lines. Instead it was decided to use artillery to keep the population at arms length - and “weaken it with terror and growing starvation”.