Hay Festival 2012: Hilary Mantel: Cromwell is a work in progress So why build a massive project around an ugly Tudor politician, condemned by posterity as a corrupt torturer? The first thing to say is that when I began I felt that I could cut Cromwell down to size. I intended one novel, to take him through from his obscure birth around 1485 to his death on the scaffold in 1540. I meant to trace his path from his origins in Putney, where his father was a brewer and blacksmith, though the serpentine twists of fortune that brought him to Henry's right hand and made him one of the major architects of the English reformation. I meant to follow him to wealth and power and magnificence, then stand back and watch as the king turned his back on his newly created Earl of Essex: as he sent Cromwell's enemies to pull his house apart and impound his papers, as he bundled him into the Tower and (after a period of weeks for him to complete the work on the current royal divorce) sent him to the scaffold, where, according to one source, he was butchered by an incompetent executioner. But fiction is inherently unpredictable. Even when you know the end of the story, you don't know how you're going to arrive there. There is a choice of route maps, but at a fork in the road you hesitate; the scenery is not as you imagined. The plain straight line on the paper is obscured, in reality, by dense thickets, and the ground under your feet, reassuringly solid when you began, now feels marshy, quaking. When I began to write Wolf Hall, I jumped, within the first unpremeditated line, behind the eyes of a 15-year-old boy, lying on the ground in his own blood, at the mercy of his father's fists and feet. "I was a ruffian in my younger days," Cromwell said; it was perhaps the only piece of autobiography he proffered. I took him at his word and made him a ruffian. I had no quarrel at that stage with his status as villain. I only thought he must be interesting. But once I had made that fictional leap, I was pulled away from the easy, received version. The picture changed. My character scraped himself up from the ground and staggered into his future. From behind those small eyes, the sharp eyes of a good bowman, the Tudor world looked complex and unfamiliar. The angles were different. Light and shadow fell in unexpected places. I saw that the man in Holbein's painting was a man inured to loss. He was in his late forties at the time of the painting. His wife and daughters were dead, gone most probably in the epidemics of the late 1520s. The loss was not, by the standards of the time, particularly remarkable, but he did not marry again or try to replace them. He had tied his fortunes to those of Thomas Wolsey, the king's cardinal, the flamboyant and charismatic minister who dominated the political scene until Henry turned against him and broke him in 1529. It was a proceeding of craven ingratitude on Henry's part, and Cromwell, who loved the cardinal, had to fight to survive him: a hard man, a determined man, and one with little to lose. He set out to win over Henry and to make himself indispensable. "I will make or mar," he said, picking himself out of the wreckage. It was, said a contemporary, "ever his common saying." The awful fascination of this making, this marring, riveted my attention, and when I gota little over half way through Wolf Hall, I saw - not gradually, but in a flash of insight - that one book would not tell this story. The battle for England's soul was under way. England had broken from Rome. Anne Boleyn was queen. The king's favourite, Thomas More, was locked in the Tower, wrestling with his conscience, while Thomas Cromwell tried to tempt him to the side of life, to a capitulation to Henry's will. The story is more nuanced than the one familiar to us from A Man for All Seasons. More's death was a defeat for Cromwell; More's surrender would have been his victory, a glorious propaganda coup for the new church. In the teeth of Cromwell's efforts, More organised his own martyrdom. Once I began to see the complexity of the contest between the two men, my story could not hurry past it. It was the climax of the narrative, and after it the reader must put down the book. So: there will be a second novel, I told my bemused publisher. It will take us from the day of More's execution to Cromwell's own end, some five years. I should not have been so certain. Last autumn, writing the story (overfamiliar, you would think) of the final days of Anne Boleyn, I found myself rigid with tension and rinsed by fear. It is the privilege of the imaginative writer not to retell but to relive. It did not feel like a privilege to inhabit those rooms alive with whispers, pattering with footsteps: running feet scurrying to desert, the feet of men and women rushing to save themselves. In Anne's last days courtiers were ready to slander and twist and lie. The court was seething with unspeakable secrets that were, nevertheless, trying to speak themselves. About a fortnight (in writer's time) before Anne was due to die, I made another sudden and alarming discovery. The head that was to fall was Medusa's head and its glance would turn my project to stone. I had, in fact, written a second book, and with the arrest of Anne it was almost complete. Whereas the action of Wolf Hall sprawls across the borders of Europe and spans more than a lifetime, Bring up the Bodies directs the reader's attention to the events of nine months, and within that nine months to an intense period of three weeks; and within that three weeks, to the hour, to the instant of compromise and betrayal, to the loose word and the flickering thought that changes history's course. At the end of the book, the king has his heart's desire: a third wife. Cromwell has given him what he wanted, but for both king and minister there is a price to pay. The last chapter is called Spoils. In the political arena, no victories are uncomplicated, and all contain the seeds of defeat. And on the personal level, the ghosts who trail Cromwell are joined by another spectre, the quicksilver phantom of a laughing, narrow-bodied woman, who clasps her hands around her throat and says, "I have only a little neck." I am still surprised to find that I am writing a trilogy. The Mirror & the Light will (I swear) conclude the enterprise. It will have taken a decade. Sometimes people ask me what I think now of Thomas Cromwell. Nothing, is the answer. I don't think anything. He is a work in progress. I am not in the habit of writing character references for people I only half know. When I've finished, and he's decapitated, and a year has elapsed, I might be able to tell you. I am not claiming that my picture of him has the force of truth. I know it is one line in a line of representations, one more copy of a copy. All I can offer is a suggestion: stand here. Turn at this angle. Look again. Then step through the glass into the portrait and behind those sharp eyes: now look out at a world transformed, where all certainties have dissolved and the future is still to play for. Hilary Mantel is at the Hay Festival Saturday 02 June at 1pm; hayfestival.org. To buy Bring Up the Bodies (Fourth Estate, £20) at a discounted price, call 0844 871 1515 or go to books.telegraph.co.uk