Few westerners have heard of the greatest battle of the second world war, fought on a scale never matched in western Europe or Africa. The Russians wrote the battle of Moscow in 1941 out of their history books after their suicidal bravery smashed the myth of German invincibility.

More than 7m combatants on both sides took part, compared with the 4m who fought at Stalingrad in 1942-43 and the 2m at Kursk in 1943. The Soviet Union lost more people — 926,000 soldiers killed — than the British lost in the entire first world war.

It was the price they paid for inflicting on the Wehrmacht its first real defeat, hurling the Germans back hundreds of miles. Yet shame brought about collective amnesia. That omission has been rectified by our former man in Moscow, Sir Rodric Braithwaite, whose book, Moscow 1941, reconstructs the battle through scores of interviews with Muscovites whose lives were scarred by the experience.

Braithwaite himself lived through tumultuous times when, as ambassador from 1988-92, he witnessed the flowering of perestroika, the attempted coup against Mikhail Gorbachev and the collapse of the Soviet Union. Later, as a former chairman of the Joint Intelligence Committee, he was an outspoken critic of the “dodgy dossier” used to justify the Iraq war. Braithwaite now seems to have thought better of his scathing attack. “I think I would have done the same as John Scarlett did and I think it would have been the wrong thing to do,” he says. Now that’s real diplomacy.

Despite being a Russian speaker who had his first posting to the Soviet bloc in 1959, Braithwaite’s knowledge of the battle of Moscow had been minuscule.

So why was it hushed up until comparatively recently? The explanation is a story of self-delusion. Joseph Stalin, the Soviet dictator, had concluded a non-aggression pact with Hitler. Even when the Wehrmacht was massed at the border, he was in denial.

“He felt that the Red Army wasn’t ready after all the purges and the huge expansion of the armed forces,” Braithwaite says. “They needed time to settle down. He couldn’t afford to believe he would be attacked before he was ready.”

On paper, the Russians were more than a match for the force poised on their border. The Germans had more than 3m men, nearly 2,000 aircraft and more than 3,000 tanks. But with 4m men, the Russians had more guns and mortars, more than twice as many tanks and three times as many aircraft.

Initially, the blitzkrieg attack in June 1941 left the Russians in disarray. The Red air force lost more than 1,200 aircraft on the first morning. Stalin performed the equivalent of hiding under the bed, retreating to his dacha for 36 hours until his rattled commanders demanded his return. Incompetence, panic and a refusal to acknowledge reality characterised the Russian high command. This accounted for official amnesia about the battle.

“Stalin kept his head down until victory was assured after the battle of Stalingrad. So he wasn’t keen on glorifying (the battle for Moscow) and it has been played down in the Russian consciousness,” Braithwaite says.

A fear that the peasants would not fight proved misplaced. They did not need commissars to prod them into battle: not only peasants, but tens of thousands of ordinary people flocked to volunteer. The Germans were shaken when these novice troops threw themselves in “suicidal waves” at the invaders, even when fighting had become pointless.

On the outskirts of Moscow the Germans ran out of steam. The mud, the cold and Russian ferocity had ground them down. They had lost the strategic initiative for the first time since 1939, and it was downhill from then on.

Moscow 1941: A City and its People at War by Rodric Braithwaite is published by Profile Books on April 6 at £25. Copies can be ordered for £22.50 with free postage from The Sunday Times BooksFirst on 0870 165 8585