Stalingrad is built along the west bank of the Volga, and it is a very odd shape: about thirty miles long and rarely more than three miles wide, a ribbon of factories and housing between the river and the steppe.
That shape matters more than anything else in this story. There was nowhere to retreat to. Behind the defenders was a river almost a mile across.
The city was reached in August nineteen forty two, at the end of a summer offensive that had covered enormous distances. On the twenty-third of August the German air force flew around a thousand sorties against it in a single day, and the city burned. The civilian population had not been evacuated, on orders, and tens of thousands of people died in those first raids.
Then the German army walked into the ruins, and the ruins turned out to be the problem.
The German army in nineteen forty two was extremely good at a particular kind of war: fast movement, tanks concentrated, aircraft overhead, encircling an enemy in open country.
None of that works in a ruined city.
Tanks in streets are blind and can be attacked from above and behind. Aircraft cannot bomb a building your own men are inside. Radio does not reach through rubble. Maps become useless within days because the landmarks have been knocked down.
What replaced it was fighting for individual buildings, then individual floors, then individual rooms, with grenades and small arms at a range of a few yards. The German soldiers had a word for it. They called it Rattenkrieg, the war of the rats.
The Soviet commander in the city, Vasily Chuikov, made a deliberate tactical decision that sounds insane and was not. He ordered his men to hold their positions as close to the German lines as physically possible, sometimes a single street or a single wall away. He called it hugging.
The purpose was to make air support and artillery impossible. A bombardment on a position that close would kill both sides, so it was not delivered, and the single greatest German advantage was cancelled by proximity.
The best-known example is an ordinary four-storey apartment block near the river.
A small group of Soviet soldiers took it in late September, under a sergeant named Yakov Pavlov, and held it. The building sat on a square with clear fields of fire and it commanded the approaches to the river crossing, which made it worth an enormous amount to both sides.
The garrison, never more than a few dozen men, fortified it: mines in front, barbed wire, machine guns in the windows, holes knocked through internal walls so they could move between rooms without going into corridors, and a trench dug back toward the Soviet lines for supplies.
They held it for around sixty days.
There were civilians in the basement for part of that time, which is a detail that gets left out of the retellings and should not be.
German maps of the city are said to have marked it as a fortress. It was a block of flats.
Everything the defenders had came across the Volga, and the crossing was the most dangerous half hour in the battle.
Boats and barges went at night, loaded with ammunition, food and replacements, and came back with the wounded. The far bank held the artillery, which fired over the river into the city.
By November the Soviet-held part of Stalingrad was in places a strip only a few hundred metres deep, backed against the water. On the German side, reports going to Berlin repeatedly announced that the city had all but fallen, and each time there turned out to be another factory still holding out.
Among the units ferried across were a great many very young replacements who had been in uniform for a few weeks. The order they were given on the east bank was simple and is quoted in almost every account: there is no land for us beyond the Volga.
Then the river began to freeze, which was worse than either state, because ice floes made boats impossible and the ice was not yet thick enough to walk on. For several weeks in late autumn the defenders were very nearly cut off entirely.
While all of that was happening, the Soviet high command was doing something else, quietly, a long way away.
The German Sixth Army was concentrated in and around the city. But an army in a city has flanks, and those flanks stretched out for hundreds of miles across open steppe to the north-west and the south.
Those flanks were not held by German troops. There were not enough. They were held by Romanian, Italian and Hungarian armies: allied forces that were short of anti-tank weapons, thinly spread, and dug into open ground.
Soviet planners had been building a reserve since September, unnoticed, and on the nineteenth of November they attacked the flanks.
The operation was called Uranus, and it did not go anywhere near the city. Two enormous pincers went through the Romanian armies on either side and drove toward each other across open country behind the German position.
They met four days later, at a town called Kalach. Everything inside the circle, around a quarter of a million men, was cut off.
It took only four days because there was very little in the way. The German armour that might have stopped it was inside the city, in the rubble, fighting for a factory.
The encircled army was told to hold where it was and wait for relief, and was promised that it would be supplied by air.
The air supply was never remotely possible. The requirement was several hundred tons a day and the average delivered was a fraction of that, in a Russian winter, against fighters, from airfields that were themselves being overrun.
A relief attempt in December got to within about thirty miles and was stopped.
Through January the pocket was squeezed. The last airfield was lost on the twenty-third. Field Marshal Paulus surrendered the southern part of the pocket on the thirty-first of January, nineteen forty three, and the northern part gave up two days later.
About ninety-one thousand men went into captivity. They had been through a winter without adequate food, clothing or medicine, and many were already beyond saving. Of those ninety-one thousand, somewhere around five thousand eventually came home, and most of those not until the mid nineteen fifties.
Total casualties on both sides, over the whole battle, are usually estimated at close to two million, including civilians.
Stalingrad is generally treated as the point where the war in Europe turned, and the reason is not only the size of the loss. It was the first time a German field army had been destroyed entirely, and the first public admission at home that something had gone catastrophically wrong. Three days of national mourning were declared.
There is a famous photograph taken shortly after the raids of August nineteen forty two: a fountain in a square in front of the wrecked railway station, with a ring of sculpted children dancing around a crocodile, still standing in the middle of the rubble. It was a children's fountain in a destroyed city, and it became the image everybody remembers.
Yakov Pavlov survived, was made a Hero of the Soviet Union, and lived until nineteen eighty one. The building he held was rebuilt after the war, and part of the original wall was kept and built into it as a memorial. People live in it now.
Here is something to think about tonight. For five months both sides poured everything they had into a few square miles of ruins, and the battle was actually decided by an attack that took place a hundred miles away against somebody else. How do you stay aware of the thing you are not looking at?