Tudor terror: John Guy is on a mission to bring history to the masses

Forgery, forgotten evidence and mouse-droppings – Tudor expert John Guy has made all sorts of unsavoury discoveries down in the National Archives. He tells Mark Bostridge why he's on a mission to bring Tudor history to the masses, and where David Starkey got it wrong

(Kalpesh Lathigra)

It is the summer of 1535, just weeks after the execution of Sir Thomas More. A small rowing boat makes its way along the Thames from Chelsea to London Bridge. The oarsman's passengers are a 29-year-old gentlewoman, Margaret Roper, and her maid, who carries a basket. A horrific sight meets their eyes as they approach the bridge: a dozen or more skulls on poles protruding from the parapet, which have been boiled and tarred to prevent them being fed upon by circling gulls. As new heads arrive, the old ones are moved along the row until they reach the end of the line, when they are thrown into the river.

At the door of the north tower of the bridge, the maid negotiates with the bridge-master, handing over the contents of her purse. In return she receives one of the skulls, carefully wrapping it in a linen cloth and placing it in a basket. This is all that remains of Thomas More. One day the skull will join Margaret Roper herself, when she is interred in the family tomb at Chelsea, a burial symbolic of the special attachment between father and daughter.

This is the gripping opening scene of John Guy's study of the relationship of Margaret Roper and her father, Thomas More. Such a grisly depiction of the past seems all of a piece with John Guy's historical method. As a writer Guy has sometimes been accorded the epithet "Chandleresque", a tribute to the forensic skills with which he sets about revisiting and reinvestigating the scene of a historical crime, and to the pacy, atmospheric narrative in which he places his discoveries.

Four years ago, Guy carried off the Whitbread Biography Prize for his thrilling dissection of the life of Mary, Queen of Scots, My Heart is My Own. Had Mary really been complicit in the assassination of her second husband, Lord Darnley, at Kirk o'Field in 1567, he asked, or was she framed by agents of the Scottish Crown, the Confederate Lords, anxious to replace Mary's rule with a regency in the name of her young son James? By subjecting the Casket Letters, so long reputed to establish Mary's guilt, to rigorous analysis, Guy was able to reveal the letters as a clever forgery. In some instances, forged passages – designed to prove Mary's part in Darnley's murder – had been interpolated into genuine letters in Mary's handwriting.

Now Guy has turned his attention to another story from Tudor history, that of the opposition of Thomas More, the former Lord Chancellor, to Henry VIII's marriage to Anne Boleyn, his arrest for treason, and his martyrdom. As before, Guy's scholarship is irreproachable. He admits to being never happier than when he is scrutinising some vital document which will enable him to throw new light on a familiar version of events. "Sometimes this means that I have literally to get my hands dirty." He tells me that 16th-century documents in the National Archives are often covered with damp and the traces of vermin, and one doesn't always have the protection of gloves, though he adds that modern techniques, such as ultra-violet light, can yield unexpected dividends in the examination of papers that are simply too damaged to read with the naked eye.

From a host of unprepossessing legal documents, through which we can glimpse the small-scale workings of Tudor society, as well as from a series of more idiosyncratic sources, such as the interrogation records of More's servants while their master was under arrest in the Tower, Guy has produced a compelling portrait of a tyrant's court, in which the king's friends had far more to fear than his enemies. Guy's Henry is a Stalin-like figure, bullying and intimidating his closest associates, fixing juries and resorting to all sorts of chicanery to achieve his will.

Central to Guy's book is the part played in the drama by More's favourite child, Margaret. "She has been airbrushed out of the public events of More's life," Guy says, "and confined to scenes of the More family's domestic life at Chelsea. Yet, during his imprisonment, Margaret was his sole intermediary with the outside world, and without her support More could never have continued his heroic struggle against the king. It is to the letters they wrote to one another, to those she smuggled in and out of the Tower during her visits, and to Margaret's energy in preparing an edition of her father's collected works after his death, that we owe much of what we know about Thomas More today. In Holbein's famous portrait of the family, Margaret sits with a book open on her lap. She is, if you like, the storyteller – and what an emotional story it is."

John Guy always knew that he wanted to make Tudor history his career. Born in 1949, in Warragul, Australia, where his father, an engineer, was on an assignment "fixing cranes", Guy returned to England at the age of three and was raised in Lytham St Anne's. In the late 1960s, he went up to Clare College, Cambridge, and came under the spell of the preeminent Tudor historian of the time, G R Elton.

However, unlike his slightly older Cambridge contemporary, David Starkey, who also studied under Elton, Guy never turned against his mentor. He remains full of "admiration and affection" for Elton, while conceding that he could be something of a "control freak". He further admits that the Eltonian model of 16th-century English history, with its concentration on administrative and institutional structures, and its insistence on a Tudor Revolution in government piloted by Thomas Cromwell, is far removed from the kind of history he himself currently writes, addressed to a general readership who have had their appetites whetted by the dramatic, vivid presentations of Henry VIII's reign that they have seen on television.

Twenty years ago, Guy, then still a full-time academic at Cambridge, published Tudor England, the first full-length study of the period for decades, which has sold a quarter of a million copies to date, and remains an influential textbook for undergraduates. Today, while he still teaches part-time, his approach to the subject has undergone a sea-change. Television, including his own involvement in documentaries for the BBC's Timewatch strand, has helped him appreciate that history can be written in a more inspirational way, though he now thinks that TV is too bent on "sensationalising" the past. As an academic, Guy had already written two books on Thomas More's public career, but I sense that what attracts him most to the story nowadays are the novelistic elements in it – underpinned, of course, by scholarship. At home in north London, Guy and his wife Julia Fox, who last year published a biography of Jane Rochford, nemesis to two of Henry VIII's queens, Anne Boleyn and Catherine Howard, are a veritable Tudor production house.

One of the myths that Guy's book destroys is of the idealised picture that has come down to us of the More family as a cosy, supportive unit. In fact, like any family, this one was riven by internal disputes, chiefly about religion (the new Lutheran faith) and money.

What of the "man for all seasons" himself? Despite Pope John Paul II's nomination of More, in 2000, as the patron saint of politicians, More's unrelenting campaigns against Protestant heretics have come under renewed scrutiny in recent years, challenging his reputation as a humanist intent on equality of justice for all.

The figure of Robert Bolt's play and film, so popular for the counter-culture of the 1960s, may have had his day, Guy admits. But there is no doubt whatsoever in Guy's mind that, in the shadow of the block, and with the steely resolve of his daughter behind him, Thomas More became a hero of conscience. "When the chips were down, he remained a conscientious objector and stayed an honest man."

The extract

A Daughter's Love: Thomas and Margaret More, By John Guy (Fourth Estate £25)

'...Times were changing. Not for nothing would Margaret's descendants compare Anne to Salome, who'd called for the head of John the Baptist. Incensed by More's boycott, Anne thirsted for revenge after discovering that, although some friends of his had urged him to attend her coronation and he'd accepted £20 from them to buy a new gown, he'd stayed at home, jesting with his benefactors'