The lifting of the taboo on discussion of the murder of the Imperial Family has been accompanied by the opening of archives that were inaccessible under Communist rule. Many of the documents published here by Maylunas and Mironenko, the director of the Russian State Archive in Moscow, were previously only available in excerpts smuggled out of the Soviet Union, or were rumoured to have been destroyed altogether. The Tsar's diaries, begun at the age of 14 and kept for 36 years without interruption, were taken to Moscow after his death by a "secret courier", the chief executioner, Yurovsky, together with 630 letters written by Alexandra to the Tsar in the course of more than 20 years of marriage, discovered among her belongings at Ekaterinburg.
While these form the backbone of A Lifelong Passion, it is the chorus of contemporary voices - those of crowned heads and foreign ambassadors, Grand Dukes and Duchesses, revolutionaries and murderers - in official documents, letters and memoirs, which really give the book its sense of gripping immediacy, and turn it into such an engrossing drama. The perspective is constantly shifting, and we view crucial events like the murder of Rasputin from the multiple vantage-points of police reports, and the horror-struck, sometimes contradictory, memories of the assassins themselves, who after poisoning, shooting and beating Rasputin, are astounded by his "diabolical" refusal to die.
This saga of the last years of Tsarism also brings to life the struggles of an autocratic regime failing to come to terms with the modern world. The intrigues and in-fighting at court, the Tsar's unquestioning acceptance of his divine right to rule, and his and Alexandra's almost mystical fatalism, are vividly illustrated. The cast of subsidiary players also lends colour to the narrative. The Tsar's cousin, George V, insists that Nicholas wear high heels so that Alexandra won't tower over him; the Tsar's Uncle Konstantin, known as "the best man in Russia", is revealed in his journal to have been a regular visitor to the Moscow bath houses where he indulged his "depraved passion" for young boys; and there are the pathetic voices of the four young Grand Duchesses and the Tsarevitch: childish, affectionate, and full of enthusiasm for family life.
What of the "lifelong passion" of the title? There can be no doubting the genuine ardour that lay behind the public affection of Nicholas and Alexandra ("Huzy" and "Wify"), though conventional expression and reiteration make their more intimate letters one of the less involving elements of the book. Nicholas's diaries, too, are just what one would expect: terse and monotonous, with comments about the weather and the number of birds he has shot.
Alexandra emerges as the more compelling character. Shy and reserved, she never inspired general adulation in her adopted country, although the outstanding features of her personality - morbidity, violent swings of mood between despondency and elation, and "superstitious credulity" - were characteristics which were able to take strong root in Russian soil. As her own health suffers through nervous worry about the Tsarevitch's haemophilia, and she becomes increasingly dependent on Rasputin as the one person she believes can save her son's life, it is difficult not to feel some sympathy.
Even when she is at her most neurotic and misguided, writing page after page to the Tsar during the war, trying to wield political influence and prevent him from being weak and vacillating, she remains somehow a commanding figure, veiled, as one contemporary put it, "in a shadowy incomprehensible aura". What lies in store for us, she keeps asking: what will our lot be? Part of the power of this book is that we know how it will all end, in a hail of bullets in the cellar in Ekaterinburg. Before one is a quarter of the way through, one feels that one can already sense the inexorable, headlong rush towards tragedy.
Six years ago, I visited Sotheby's to view the archive of Nikolai Sokolov, the White Russian judge appointed to investigate the Bolsheviks' murder of the Tsar and his family. There were the coded telegrams from Moscow which prove that Lenin himself approved of the killing of the Romanov children, and I held a fragment of the yellow and cream wallpaper from the room in which the family were put to death.
Last month's return of the Sokolov archive to Russia marks another stage in the country's coming to terms with its recent history, and with its regicide. The publication of these documents is a small part of this process which will continue until all the loose ends relating to the events of almost 80 years ago have been tied up. Then it will be time to allow the Romanovs their quietus.