As a historical novelist, Hilary Mantel is no minimalist. A previous foray into the genre, A Place of Greater Safety (1992), compressed the drama of the French revolution into 900 bulging pages. In her new book, a bustling account of England’s Reformation, she restricts herself to just 650. Modest enough, you might think, until you reach the final chapter and realise we are still in 1535 and there are at least five more years to be squeezed into a promised second volume.

The individual through whom Mantel channels her portrait of these tumultuous times is Thomas Cromwell, Henry VIII’s chief enforcer during the 1530s and a man who has often been harshly treated by history (the title of a recent book, Thomas Cromwell: Machiavellian Statecraft and the English Reformation, gives some idea of his equivocal reputation). Wolf Hall, a vibrant, often compelling mix of the personal and the political, wants to rescue him from the mud into which some historians have thrown him, while also exploring the tangled loyalties, moral confusions and shifting sensibilities of the period.

Cromwell is an arrestingly complex figure in Mantel’s retelling. When we first meet him, as a youth, he is on his face in the Putney grime, being kicked half to death by his violent, drunken blacksmith father. When he next appears, one chapter and 27 years later, it is as Cardinal ­Wolsey’s fixer, a calm, judicious and occasionally sly and threatening figure who has put his years abroad ­­— as a soldier, merchant and polyglot financier — to good use in conducting his master’s business. As Wolsey falls, as Anne Boleyn plots to replace Catherine of Aragon as Henry’s wife, as the Protestant sect gains ground over the one true faith, and as the court shifts and shifts again around the capricious king, we watch the lowly Cromwell rise up the pecking order, to the confusion of those around him. (“Where does the fellow spring from,” a bemused Duke of Suffolk asks Henry.)

What makes Cromwell particularly attractive is the perspective from which his story is told. Although the book is written in the third person, it is a peculiarly intimate third person, one that allows us, for nearly all those 650 pages, to feel as if we are inside his head (he never leaves the stage). As a result, he comes across as a surprisingly sympathetic character — loyal, modest, humane, considerate to women (unlike his archrival, Thomas More), a man who ­privately rails against the fraud and idleness of the monasteries. It is left to the reader — picking through the evidence, weighing Cromwell’s actions against their repercussions, comparing his actions to those of the vengeful More — to judge the morality of the man. (“Do you think I look like a murderer,” he keeps asking his friends. He might as well be addressing us.)

The book has many other alluring qualities. Mantel’s characterisation is acute — whether of the wilful and spoilt Anne, of Catherine (“rigid in her boned bodice”) or the bluff and splenetic Duke of Norfolk. Despite the novel’s length, there is, too, a remarkable compression to the style and the individual scenes, which allows events to trip over each other in the confusion of the everyday. Above all, Mantel’s recreation of the era feels both accurate and natural. By focusing, not on the famous set-pieces, but on the human interaction taking place around them, she makes the reader complicit in the drama. “The fate of peoples is made like this,” she writes towards the end, “two men in small rooms. Forget the coronations, the conclaves of cardinals, the pomp and pro­cessions. This is how the world changes.” The quote could stand as a motif for the whole book.

But — and there are two considerable buts here — such qualities bring their own problems, which Mantel fails to deal with convincingly. One is the question of ­perspective. Cromwell’s apparent benignity, despite the clues to the contrary scattered through the text, appears so overwhelming that at various points it almost undermines the entire novel. Indeed, in the last few pages, Mantel’s fondness for her man nearly tips over into sentimentality.

The other problem has to do with that question of length. One wouldn’t accuse War and Peace of being too long, but then Tolstoy had an acute sense of pace, mixing foreground and background, the wide and the narrow to telling effect. Wolf Hall (the name of Jane Seymour’s country house and the last words in the book) is much less sure on its feet here. Indeed, the way the scenes seem to crowd in on each other, the way the throng of often confusing characters passes before our eyes (the cast list runs to five pages), and the sheer volume of detail, have a deleterious effect on the whole project, slowing its pace, chipping away at its contours, softening its definition. ­Mantel spoke in an interview recently of the need for writers to be ruthless in their pruning. Despite the crispness of the individual scenes, she does not seem to have taken her own advice to heart. The effect, sadly, is to turn a potentially outstanding novel into merely a commendable one.

Wolf Hall by Hilary Mantel
Fourth Estate £18.99 pp650

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