Rayfield charts Joseph Stalin's progression from provincial seminary student to power-hungry tyrant - cunning, cynical, highly intelligent, totally lacking in conscience, prepared to countenance almost any atrocity in the search for power, determined to crush all opposition to hang on to it -- and a jolly good personnel manager.

Stalin's ability to 'read' and promote people accordingly lies at the heart of Rayfield's approach, focusing as it does not just on Stalin himself but on five key henchmen - his secret police leaders appointed to do the dirty work and jointly responsible with their leader for some of the worst mass crimes of the 20th century.

Take, for instance, the so-called Katyn massacres of April 1940, during which 22,000 Polish prisoners of war were shot. Or the 'Great Terror' - a crackdown on free thought in the late 1930s in which around 750,000 were executed. Or the campaign against the peasantry, estimated to have cost as many as ten million lives.

Such figures are difficult to comprehend and perhaps the cruelty of the regime is better illustrated by the deviousness of those involved.

Offered their lives in exchange for confessing to trumped-up charges, alleged dissenters were routinely executed when finished with - often together with their families.

Loyalty to the regime was no guarantee of security, though, and whenever party officials fell out of favour, erstwhile colleagues would quickly queue up to denounce them.

While it is difficult to recommend this book to a general readership due to its sheer density, it is undoubtedly a highly significant contribution to our better understanding of the history of the Soviet Union, and of the bloody 20th century in general.

It also effectively serves notice on modern Russia of the need to face up to the legacy of Stalinism, for fear of replicating it.