HAD JOSEF DJUGASHVILI been shot during the daring bank raids or pirate attacks that the young revolutionary organised; had he succumbed to the widespread disease among the poor in the filthy Baku oil fields where he incited strikes and riots; or had he been stabbed in jealous rage by the comrades he cuckolded as he seduced their wives, many would have mourned.

The poor, pockmarked son of a drunken and violent Georgian cobbler had proved himself a gifted, self-taught intellectual, a precocious poet whose verses had been published to widespread acclaim, a singer with a voice so fine that he was much in demand at weddings, and a trainee priest devout – for a while – in his attendance at mass and assiduous in his seminary studies. But when Josef Stalin, the last of his aliases, died in 1953, an entire cowed nation wept.

How did Soso (Stalin’s childhood nickname) evolve from a fearless revolutionary despised as an uncouth provincial by the snobbish Bolshevik elite into the nemesis of all those early communists who once looked down on him?

Simon Sebag Montefiore’s magnificent biography traces the evolution of this slight, partially handicapped, cossetted only son from a quarrelsome street brawler into a disciplined, dedicated ideologue, who let nothing – not romance, drink, danger or friendship – deflect him from the path to absolute power.

The man who could take merciless advantage of human weakness, who could mask his emotions, hide his intentions behind a beguiling persona and exploit the trust of those less cunning or suspicious than himself impressed all those who fell under the sway of the Bolshevik visionary with the burning eyes: women were captivated, Georgian nationalists and intellectuals impressed, tsarist intelligence agents wrongfooted.

Soso, the quick-witted autodidact who devoured Shakespeare, Zola, Plato (in Greek), Dostoevsky, Gogol, Chekhov and, above all, Marx, was also the thug who preferred the company of gangsters to intellectuals, who plotted murders and ordered shootings to eliminate rivals and impress the only man whose approval he sought – Lenin.

Young Stalin is a masterpiece of detail. Sebag Montefiore has unearthed documents long lost in Georgian archives, found the descendants of Soso’s friends and co-conspirators, weighed the evidence of detractors and Soviet hagiographers and produced a vivid psychological portrait of this dangerous, alluring, enigmatic man who, like Macavity, could vanish from the scenes of the outrages he masterminded – as he would, years later, when plotting the purges.

There is so much so surprising about the young Stalin. He was a tender and passionate lover, who bitterly reproached himself for his neglect of Kato, the wife who died in his arms, pitifully young and ill from typhus, after a brief, happy marriage and one son.

He travelled incognito to Western European capitals as a Bolshevik conspirator, including a three-week spell in dank, foggy London where he was beaten up by East End dockers and attended a soiree in Chelsea where Ramsay MacDonald toasted the Russian revolutionaries. Though often morose and prudish, he was as forgiving of sexual pecadillos in others as he was vengeful in repaying ancient slights.

The book moves with pace and authority: inevitably, there are too many walk-on characters and muddling Georgian names – but even the footnotes are packed with anecdotes deserving a whole chapter.

One comes away attracted and repulsed. Soso, brave, clever, morally and politically ambigious (was he also a tsarist agent?) is, by 1918 at the end of the book, Stalin: Lenin’s indispensible fellow revolutionary and the megalomanic rival of Trotsky, that other self-appointed Marxist messiah.

Later, came absolute power – in a chilling epilogue, Montefiore details the terrible consequences, for old friends, party colleagues, family and a country that paid the price with 20 to 25 million dead.

Young Stalin by Simon Sebag Montefiore

Weidenfeld, £25; 496pp

Buy the book here for the offer price of £23 (free p&p)

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