Whenever anyone sets about compiling a list of great figures in British history, Henry VIII is a cert. A few years ago, he was at number 40 in a BBC poll of 100 great Britons, and more recently he's played a leading role in Hilary Mantel's prize-winning historical novels. The final instalment of the trilogy will have to deal with Henry's decision to execute Mantel's hero, Thomas Cromwell, who was despatched on the same day Henry married his fifth wife, Catherine Howard. She lasted less than two years before following Cromwell to the scaffold, and I'm not remotely surprised to hear that Henry has now been diagnosed as a psychopath.
According to Professor Kevin Dutton, Henry scores 174 on a "psychopathic spectrum" which starts at 168 (the "average" male scores 112). In The Wisdom of Psychopaths, out in paperback this autumn, Dutton looks at 10 historical figures, including Winston Churchill and Charles Darwin. The Tudor king is his only "bona fide" example: Henry scores highly for emotional detachment and cold-blooded ruthlessness, which Dutton says are characteristics of "dangerous psychopaths".
I've always been amazed by the ease with which Henry's admirers glide over these aspects of his character, casting him either as a jovial fat monarch – bluff King Hal – or a complex soul whose shortcomings are outweighed by his statesmanship. If I were in search of a modern parallel, I'd suggest that the atmosphere of Henry's court probably resembled Saddam Hussein's Baghdad, where yesterday's favourite was today's traitor.
Look at the record: there were 330 political executions between 1532 and 1540 alone, and the historian Ronald Hutton suggests that Henry's reign probably saw more such executions than any of comparable length in English history. Many of the king's victims were once his closest associates, including two of his wives, a sister-in-law and two chief ministers; Cardinal Wolsey died before he could be tried for treason but neither Cromwell nor Sir Thomas More were so lucky. A musician called Mark Smeaton was tortured on the rack before being executed with four other men accused of being Anne Boleyn's lovers, including her own brother.
Historians hate it when famous people from previous centuries are looked at through modern eyes, but I don't think human nature changes that much. Poor Catherine Howard was probably only 17 when the king married her and 19 when he had her executed for infidelity. As well as going in for domestic violence on a grand scale, Henry had Cromwell's severed head displayed on a spike on London Bridge.
It'll be interesting to see how Mantel deals with this, but the 20th-century parallels – murderers keeping body parts as trophies – are insistent. If anyone feels like producing a realistic account of this horrible monarch, I've already thought of the perfect title: Henry VIII: Portrait of a Serial Killer.