Long before Mary, Queen of Scots, had her head chopped off, Anne Boleyn had the misfortune to lose hers.

There is of course an irony in the fact that Mary was decapitated by order of Anne's daughter, Elizabeth, who in many other respects was the antithesis of her mother's husband, Henry VIII. But when he and she needed to be ruthless, they were very much alike. Such was regal life in 16th-century England.

Anne is one of the three principal characters in this sequel to Hilary Mantel's Man Booker winner, Wolf Hall. The other two are the aforementioned Henry and Thomas Cromwell, who preside over a court which has startling similarities to that which resonates even today in the incestuous and barbaric kingdom of Saudi Arabia, a country whose misogynistic customs Mantel knows only too well.

At the outset of Bring Up The Bodies, in 1535, Henry is 44 years old and married to his second wife, Anne Boleyn, a union which has caused major ructions, not least with the Pope in Rome. In public, sitting astride a horse, Henry seems as secure as he does on his throne. Looks, however, deceive. At night, he lies awake, numbering his days, fearing for his soul and anxious over what his enemies might be plotting.

Cromwell, the conduit through whom events unfold, is about 50 and, like his master, running to fat. A self-made man in the mould of a smooth-talking Mandelson or, more psychotically, Tony Soprano's consigliere, he does whatever Henry tells him, painfully aware that his fortunes are umbilically attached to the king's.

When the king falls from his horse during a joust and is feared dead, it looks like curtains too for Cromwell, as his enemies eagerly remind him. Whether Henry was as close to death in reality as Mantel suggests is neither here nor there. What matters is that it works fictionally, reminding readers that the peg on which Cromwell's life hangs is exceedingly shoogly.

A student of Machiavelli, he is aware that to survive in the courtly nest he must be more viperous than the rest. Anne is his biggest adversary and a formidable one at that. However, her problem is her inability to give the king an heir. At least, that's how it's interpreted. That the fault may lie with Henry is unconscionable. As he tells the Archbishop of Canterbury, all ultimately that's required of him is to have a son: "If a king cannot have a son, if he cannot do that, it matters not what else he can do. The victories, the spoils of victory, the just laws he makes, the famous courts he holds, these are as nothing."

Mantel is the perfect guide through a world in which relationships overlap and family trees spread like ancient oaks. Her cast is large and the story complicated but, while she finds it necessary to sketch in background more than she might otherwise, it is done lightly, deftly and with wit. What marks her out from other practitioners of this much-abused genre is the quality and vivid earthiness of the writing. Monks, we are told, "claim they're living the vita apostolica; but you didn't find the apostles feeling each other's bollocks". The Duke of Norfolk, Anne's uncle, is likened to "a piece of rope chewed by a dog, or a piece of gristle left on the side of a trencher".

However, it is Henry on whom Cromwell concentrates most of his attention. When he sets eyes upon Jane Seymour, who will supplant Anne, he is unable to concentrate on anything else. "The king," notes Cromwell, who is forever reading his face, as all good secretaries do their boss's, "is wearing an expression he has seen before, though on beast, rather than man. He looks stunned, like a veal calf knocked on the head by the butcher."

What Henry saw in plain and pallid Jane continues to tax historians. Likewise, history has not always been consistent in its assessment of him. Mixed is perhaps the best word to describe the reviews he has received. Nor is Anne more clearly defined. Mantel portrays her as a schemer, surrounding herself with loquacious and lubricious young men with whom she may or not be sleeping. Her role is that of a carrier of heirs but that is apparently beyond her. Does she get pregnant? On occasion it seems she does but miscarries. Then again she may just have put on weight. So much in Tudor England rested on the capability of a woman's body. "God should have made their bellies transparent," remarks one courtier, "and saved us the hope and fear. But perhaps what grows in there has to grow in the dark."

Where historians hate vacuums, novelists embrace them. There is, however, a terrible inevitability about Anne's demise which never ceases to shock. Cromwell's part is ostensibly that of facilitator, of yes-man, but there is too much at stake for him personally to allow her to survive. Mantel reserves the best of her writing for those scenes between prosecutor and accused, each knowing where defeat will lead. There can be no escape for Anne and the others in her entourage. "The king," we are told, "doesn't want to think of her lovers, past or present. He has wiped them out his mind. And her too." As for Cromwell, he lives to fight another day, to furnish us with another of Hilary Mantel's extraordinary evocations of the past. But as every schoolchild ought to know, the chance of him keeping his head when all around are losing theirs is improbable.

Bring Up The Bodies

Hilary Mantel

Fourth Estate, £20