Guderian favoured from the beginning the strategic use of panzer forces - a deep thrust into the enemy, without worrying about a possible threat to his own unprotected and far-extended flanks. That was why he planned to transport all supporting elements of the panzer forces (infantry, artillery and engineers) in a similar way - that is, on tracks - and why the supply services (petrol, ammunition, food) were organically incorporated with the fighting troops. This enabled them to accompany, and keep up with the tank core until fused with it - at the same tune assuring Guderian's own supplies for three to five days.

Tanks must be fast. That, I would say, is the most important lesson of the war in regard to tank design. The Panther was on the right lines, as a prototype. We used to call the Tiger a 'furniture van' - though it was a good machine in the initial breakthrough. Its slowness was a worse handicap in Russia than in France, because the distances were greater.

The Stalin tank is the heaviest in the world; it has robust tracks and good armour. A further advantage is its low build - it is 51 cm lower than our Panzer V, the Panther. As a 'breakthrough' tank it is undoubtedly good, but too slow.

It was at Targul Frumos that I first met the Stalin tanks. It was a shock to find that, although my Tigers began to hit them at a range of 3,000 metres, our shells bounced off, and did not penetrate them until we had closed to half that distance. But I was able to counter the Russians' superiority by manoeuvre and mobility, in making the best use of ground cover.

Fire-power, armour protection, speed and cross-country performance are the essentials, and the best type of tank is that which combines these conflicting requirements with most success. In my opinion the German Panzer V, the 'Panther', was the most satisfactory of all, and would have been dose to the ideal had it been possible to design with a lower silhouette. A main lesson I learned from all my experience was that much more importance should be placed on the speed of the tank on the battlefield than was generally believed before the war, and even during, the war. It is a matter of life or death for the tank to avoid the deadly effect of enemy fire by being able to move quickly from one fire-position to another. Manoeuvrability develops into a 'weapon' and often ranks equal to firepower and armour- protection.

The advance of a Russian Army is something that Westerners can't imagine. Behind the tank spearheads rolls on a vast horde, largely mounted on horses. The soldier carries a sack on his back, with dry crusts of bread and raw vegetables collected on the march from the fields and villages. The horses eat the straw from the house roofs - they get very little else. The Russians are accustomed to carry on for as long as three weeks in this primitive way, when advancing. You can't stop them, like an ordinary army, by cutting their communications, for you rarely find any supply columns to strike.

Hitler had a magnetic, and indeed hypnotic personality. This had a very marked effect on people who went to see him with the intention of putting forward their views on any matter. They would begin to argue their point, but would gradually find themselves succumbing to his personality, and in the end would often agree to the opposite of what they intended. For my part, having come to know Hitler well in the last stages of the war, I had learnt how to keep him to the point, and maintain my own argument. I did not feel afraid of Hitler, as so many did. He often called me to his headquarters for consultation, after that Christmastide I had spent at his headquarters by invitation, following the successful stroke at Zhitomir that had attracted his attention.

Hitler had read a lot of military literature, and was also fond of listening to military lectures. In this way, coupled with his personal experience of the last war as an ordinary soldier, he had gained a very good knowledge of the lower level of warfare - the properties of the different weapons; the effect of ground and weather; the mentality and morale of troops. He was particularly good in gauging how the troops felt. I found that I was hardly ever in disagreement with his view when discussing such matters. On the other hand he had no idea of the higher strategical and tactical combinations. He had a good grasp of how a single division moved and fought, but he did not understand how armies operated.