The Battle of Stalingrad - the turning point of the Second World War - was perhaps the bloodiest battle in the history of mankind. Even conservative estimates place the number of dead at 1m. The width of the Stalingrad front advance reached 180km; while operations along the south-west front reached a depth of 150km.

For German generals, the crushing defeat of the Wehrmacht was perceived as nothing less than an ignominious fiasco. Neither they nor Hitler had been prepared for anything other than an offensive campaign.

In spring 1942 - when the German high command had begun to prepare for a campaign designed to avenge the German defeat at Moscow's gates - Field Marshall Gerd von Rundstedt suggested to Hitler that he concentrate on the defence of Germany's gains in the east, possibly even withdrawing to the Soviet-Polish border. The Fuhrer disagreed - the Moscow defeat still rang heavy for him, while a successful German offensive might have persuaded Turkey to join the war, and make an invasion of Iran possible. Hitler even proceeded to form an "F" division, fluent in Arabic and Middle Eastern languages, ready for operations in the region.

Hitler committed a lot to success in the Stalingrad operation. He persuaded Mussolini to send the 8th Italian army to the Eastern front, which was joined by the 2nd Hungarian, 3rd and 4th Romanian armies. Speaking at a conference of axis chiefs, Hitler boasted that their joint efforts "[would] deprive the Russians of their fuel bases, which would be tantamount to their absolute defeat".

Official German documents over the period 1942-3 show a belated move away from offensive to defensive operations. Indeed, starting on 23 November, 1942, when Soviet tank corps virtually encircled the 6th and 4th German armies, the papers indicate that there was a measure of panic, with the words "Russian incursion" prominent.

Field Marshall Paulus then threw in two tank divisions (16th and 24th) in an attempt to halt the Russian advance, only to see them wiped out by Russian tank defences. Seeing the reality of the situation, Field Marshall Erich von Manstein suggested to Hitler that the 6th army should break out and head west. But he was interrupted by Reichsmarschall Hermann Goering who boasted that he could transport supplies to the encircled units by air. Goering was supported by Field Marshall Wilhelm Keitel, General Alfred Jodl and other Nazi military leaders.

And when Hitler asked for the last time whether Stalingrad should be evacuated, Keitel clicked his heels and declared: "My Fuhrer, do not leave the Volga."

An operation to rescue Paulus and the 6th German army from the Soviet trap began on 12 December, 1942. But the previous day, Soviet forces had attacked German positions in the south Caucusus, and von Manstein's task force could only be joined by one reserve armoured division. He had to wait some time for more support to arrive from France. The force was clearly not enough: both Manstein's offensive near the village Kotelnikovo and Paulus's attempt to break out from the trap were doomed from the outset.

In the evening of 26 January, 1943, Colonel-General Rokossovsky's forces decimated Paulus's 6th army above the city of Stalingrad. Six days later, Paulus formally surrendered to Rokossovsky. Berlin was in mourning. Hitler realised that the Wehrmacht would never be as mighty again.

Later, officials from Goebbel's Nazi Propaganda Ministry analysed the letters of German soldiers from "Fortress Stalingrad" and were horrified to learn that only 2pc of them had remained loyal to the German military leadership.

Although Goebbels ordered the letters burnt, some of them survive to this day:

"I was shocked when I looked at the map. We are alone. There is no outside help. Hitler has abandoned us. This is the end."

"You are the wife of a German officer and must know the truth. Dirt, hunger, cold, defeat, doubt, despair and death are lurking everywhere. I am not a coward, but I wish I did not have to fight bravely for a criminal cause."

"Our division's effective fighting force has been reduced to just 69 men. The end is near. All we have is banners and dying soldiers. God, why are you doing this to us?"

The Battle of Stalingrad lasted 200 days and nights. Its outcome and its experience shook the world.

King George sent a silver, gold and rock crystal sword in honour of the great sacrifice made by the people of Stalingrad. The blade was etched in two languages with the text: "To the steel hearted citizens of Stalingrad - the gift from King George VI - in token of homage of the British people".

Though no love was lost between the British commander in chief and Stalin, Winston Churchill described the Red Army's victory as "astonishing", while Roosevelt called it an "epic battle whose result [would] be celebrated by all Americans".

RBTH dossier

The defensive phase of the battle of Stalingrad began on July 17, 1942, and lasted until November 18, 1942. The battle's offensive phase lasted from November 19, 1942, until February 2, 1943.

The battle of Stalingrad raged for more than 200 days over a territory of 100,000 square kilometres. At any one stage, the battle involved more than 2 million soldiers, 26,000 guns and mortars, more than 2,000 tanks and 2,000 aircraft.

The battle of Stalingrad inflicted catastrophic losses on both sides. The exact casualty levels are uncertain, but estimates put the number of German dead at about 1.5 million, while Soviet losses were probably at least 1.1million. According to official Soviet records, the Wehrmacht lost about 2,000 tanks and 3,000 planes; the Red Army 4,341 tanks and 2,769 aircraft.

In 1942, the Soviet military complex increased tank production to 24,668, or 3.7 times more than the year before (and more than two times the corresponding German figure). In the same year, Soviet industry produced 3,237 Katyusha multiple-launch rocket systems. Overall, in the two years following the Nazi incursion, Soviet industry in the Ural, West Siberian and Volga regions expanded production five-fold, 27-fold and nine-fold respectively.

In the summer of 1942, Stalingrad had a population of 600,000. By the end of the battle, more than 400,000 had been killed in battle, executed by the Nazis or deported to Germany. Another 120,000 were safely evacuated to the east bank of the Volga River. By the end of the battle in February 1943, it is estimated that there were just 30,000 civilians remaining in the city.