IN 1532, 1533, somewhere deep within those unchancy years, the painter Hans Holbein worked upon a likeness of Thomas Cromwell, Henry VIII’s “fixer”, the man credited with engineering the annulment of the king’s marriage to Katherine of Aragon and the subsequent break with the Church of Rome. One can visit the painting in New York’s Frick Collection, on Fifth Avenue, where it hangs on an oak-panelled wall to one side of a great stone fireplace; on the other side is Holbein’s portrait of Thomas More, beheaded as a traitor in 1535. Dressed in black robes and hat, seated at a table strewn with papers, Holbein’s Cromwell is doughy, doughty, with porcelain skin and porcine eyes which frown out of the frame towards his old adversary beyond the flames. The painting invites a question: what sort of a man was this?

Wolf Hall, the BBC’s adaptation of Hilary Mantel’s novel of that name and its sequel Bring Up The Bodies, is an attempt, over six unfurling velvet hours, to provide an answer.

In Mantel’s books we do not see Cromwell. We live inside his mind, inside his eyes, and see others as he sees them, as hearts to be weighed. Physical description of him is therefore limited. He is in his 40s, short, stocky, inclining to stoutness as he grows in social stature. He is lily pale. He looks, people say, like a murderer.

Mark Rylance is not well cast if one is looking for a perfect physical match for either Holbein’s or Mantel’s Cromwell. He is, at 55, too old. Too skinny, too puckered and sunken and seamed. Does he look like a murderer? Perhaps some mild poisoner, the sort of chap of whom a neighbour would say, later, “Such a quiet person, too”.

But Rylance brings something else to the part. What can we call it? A certain melancholy blankness. Having built a career in theatre, in seeming preference to TV and film, he is an actor from another age, a tragedian of old, and has brought from Shakespeare’s Globe to the set of Wolf Hall his tragic mask, which he wears throughout, mouth turned slightly down, expression barely altering regardless of the scene, only his eyes giving any clue to what he thinks or how he feels. In Mantel’s Wolf Hall we know all of Cromwell’s thoughts; in Peter Kosminksy’s we know hardly any of them, and must rely on Rylance’s eyes to tell us. Luckily, they are up to the job. They should be given a Bafta each.

We see this Cromwell before we hear him, a silent silhouette in an upstairs window, glimpsed during the opening credits, and then, a few minutes later, bending forward into candlelight to whisper advice in Cardinal Wolsey’s ear. This is his characteristic pose. The quiet presence in the shadows brought close to great men by their need for his strategic intelligence, and his desire for – what? Cromwell’s precise motivations are unclear, even to himself. Certainly, he wishes to rise in the world. The first words in the novel are his blacksmith father’s, “So now get up”, a roared order, emphasised by a kick to the head. He has been getting up – and up and up, all the way to Hampton Court – ever since. Wolsey, played by Jonathan Pryce, is a second father to him, one more likely to aim a blessing at his head than a curse and a boot.

The timing of Wolf Hall’s arrival on television is twice-blessed. It benefits from both a vogue for historical fiction and a post-Sopranos taste for complicated, mostly American drama built around anti-heroes, bastards redeemed, partially, by their own charisma – in the eyes of the viewers at least. Anyone seeking to identify its British antecedents should look to I, Claudius (although Wolf Hall is much more sophisticated than that often stagey production) and most of all to Alex Guinness’s wonderful portrayal of George Smiley in the le Carré adaptations of the 1970s and 80s. Indeed, an alternative name for Wolf Hall might have been Thinker, Gaoler, Soldier, Spy. It has the same languor, the same sense of cloistered, clustered male power, and it is equally willing to risk being boring.

Mantel’s Wolf Hall occupies the first four episodes of the series. Bring Up The Bodies, which covers the period leading up to the execution of Anne Boleyn and Henry’s marriage to Jane Seymour, is corseted into the final two. The novels contain, it is estimated, around 600,000 words. Peter Straughan’s script is a tenth of that, so, inevitably, there is compression and some lamentable omissions. What we lose, mostly, is the novelist’s fever for description. Bernard Hill gives a fine, volcanic Brian Blessed-esque performance as the Duke of Norfolk, but even his best efforts and that of the BBC’s wardrobe department cannot come close to Mantel’s manic piling of images: “Flint-faced and keen-eyed, he is lean as a gnawed bone and as cold as an axe head; his joints seem knitted together of supple chain links, and indeed he rattles a little as he moves, for his clothes conceal relics: in tiny jewelled cases he has shavings of skin and snippets of hair, and set into medallions he wears splinters of martyrs’ bones.”

It is a relief that Straughan has had the sense and taste to retain at least a flavour of Norfolk’s vivid oathmongering. “Oh,” he bellows at one point, “by the thrice-beshitten shroud of Lazarus!” There are a few occasions in the series like that, where ‘Wolf Hall’s’ closed air of deep seriousness is fouled by a whiff of something rather more bawdy, Bruegel overpainting Holbein, and it is the better for it.

Best of all are those moments when Cromwell and the king are alone together. Henry, as played by Damian Lewis, is a kind of monstrous child who displays all his feelings on his face – joy, jealousy, anger, fear, grief – while fatherly Cromwell, of course, shows none of that. Yet there is between the two men, the two actors, an energy present at no other time. This is the tragic love story at the heart of Wolf Hall. Henry cannot find a woman to bear him a son and heir; Cromwell, having lost his wife and daughters to disease, appears to find a consoling immersion in his work for the king. They need each other. There is, in the fifth episode, a wonderful pair of scenes in which they are first estranged and then reconciled, Henry’s pale eye flashing with rage and then regret, Cromwell’s pale skin growing paler in the eye of his master’s tempest.

History tells us that the relationship will end on the executioner’s block. The powerful Cromwell Holbein painted will become just another head spiked on London Bridge. Yet that dreadful fall will be for another novel, Mantel’s forthcoming The Mirror And The Light, and – who can doubt? – another BBC series. For the moment, it is enough to luxuriate in the stately stillness of Wolf Hall, a drama which casts a long regal shadow over the rest of British television and which, thanks in particular to Rylance’s performance, reigns supreme.