Cover of Wolf HallHilary Mantel has excelled at historical fiction before - A Place of Greater Safety, about the French Revolution, springs to mind - and this is no less a masterpiece. It concerns the court of Henry VIII, just as his thoughts move towards Anne Boleyn. Homo homini lupus - man is wolf to man - is one of the many strands that make up this work. Wolf Hall is the name of a house in Wiltshire that belongs to the Seymour family, and though they are mostly an offstage presence, they epitomise the thrusting, turbulent and plotting families that people the pages of this monumental, thrilling, powerful and uncanny novel.

The focus is on Thomas Cromwell, who "can draft a contract, train a falcon, draw a map, stop a street fight, furnish a house and fix a jury. He will quote you a nice point in the old authors, from Plato to Plautus and back again. He knows new poetry, and can say it in Italian. He works all hours, first up and last to bed. He makes money and he spends it. He will take a bet on anything." Cromwell was born into violence - the opening scene shows his father, Walter, savagely beating him - and then goes off to be a soldier, "not stopping till he gets to a war." Violence is everywhere, and Mantel shows this in her prose, which is poised and laden with power in reserve, "like the shiver you sense in the shaft of an axe when you take it into your hand."

Cromwell returns to England after a few years performing somewhat questionable deeds. Wolves gather around the court. He channels his violence and swiftly advances, first working for Cardinal Wolsey, and then, after the Cardinal's fall, as a loyal servant to Henry VIII. He also sets up a household at Austin Friars, a barricade against the darkness. The Church teeters; letters are written; the Holy Roman Emperor hovers in wait with an army; prophetesses are burned; and the whole business of divorce and the Church of England is set in motion. Mantel's almost magical ability is to detail exquisitely both the great and the miniature, the tragic (Cromwell's daughter dies "easily, as naturally as she was born. He eases her back against the damp sheet: a child of impossible perfection, her fingers uncurling like thin white leaves") and the comic (Cromwell gives Anne Boleyn a set of forks "with handles of rock crystal. He hopes she will use them to eat with, not to stick in people"). Even the humblest of objects is given character: a cheese in Thomas More's house is "pitted and wobbling, like the face of a stable boy after a night out".

People play their parts like actors. There is an epigraph from John Skelton's Magnificence, which contains allegorical characters such as "Cloaked Collusion" and "Counterfeit Countenance". Many of Mantel's cast act out scenes to each other. Henry VIII, if he wasn't a king, "could have been a travelling player, and leader of his troupe." Cromwell's mind is "peopled with the cast of a thousand plays, ten thousand interludes", and he says to Bishop Fisher, "look around you, it's all one great puppet show." This theatrical strand delves into the reality behind the smiles and the faces that everyone puts on.

Also running through the book is an awareness of history, of the occult mysteries of Britain. There is a long passage detailing it: "You can't know Albion, he says, unless you can go back before Albion was thought of. You must go back before Caesar's legions, to the . . . sins and crimes of the kings who rode under the tattered banners of Arthur and who married women who came out of the sea or hatched out of eggs." I wish there were space to quote the whole thing: it is, in and of itself, a paragon of lyricism and beauty.

We are all wearing masks, says Mantel. That rough, roistering, explosive court, which stands at the beginning of our modern history, is Wolf Hall magnified. Spies creep along every passage; a mistranslation could have you killed. It is both a metaphor and a mirror of our times. Here we lie, surrounded by packs of angry, slavering beasts; but we, like Cromwell, can learn to fight them and win.

Wolf Hall is published by Fourth Estate