Few figures in medieval history are as famous as Thomas Becket, and fewer have been subject to such utterly differing interpretations. To pious Englishmen up to the Reformation, he was a miracle-working saint, whose blood (widely available in diluted form) could heal lepers, make the blind see, and raise babies from the dead. To Henry VIII, who closed down the shrine at Canterbury and had his bones burned, he was “a rebel and traitor to his prince”. To TS Eliot, he was a strangely modern Catholic intellectual, fortified by moral and theological principles but ravaged by self-doubt. To Lewis Warren, author of the classic modern biography of Henry II (Becket’s great adversary), he was a “theological dinosaur” whose resistance to his sovereign was based on little more than “narrow clericalism”. While the interpretations are many and conflicting, the basic facts about Becket’s life are not in doubt. Born in London in 1120, he was the son of a Norman immigrant who had become a well-to-do merchant; there was money in Becket’s background but not high social status, and his aristocratic enemies would always enjoy reminding him of his humble origins. But with education and talent he was able to rise quite rapidly, working in the household of the then Archbishop of Canterbury. This brought him to the attention of the young King Henry II, who made him his Chancellor; by the age of 34, Becket was helping to run the country. Traditional accounts make much of the personal rapport between these two young men. Henry was an impulsive extrovert who loved physical activity (especially hunting), conspicuous consumption and fierce humour. Becket adopted a similar way of life, at least where hunting, hawking and luxury goods were concerned; he even had his own private zoo, with flocks of parrots and troupes of monkeys. It seems that Henry regarded him as the ideal companion and servant – not a dry intellectual or bureaucrat, but a spirited man whose own ambition made him adaptable and manipulable. But when the old Archbishop of Canterbury died and Henry appointed Becket as his successor, something changed, and a new side of Thomas Becket’s character emerged. In place of the eager royal servant, there was now an increasingly austere churchman, speaking in a language of eternal duties and rigorously defending the rights, as he saw them, of his church. Henry can hardly be blamed for failing to foresee this. Becket had not been a priest (that omission was remedied just one day before his enthronement as Archbishop), and had little theological training. If anything, his mentality was that of the brilliant lawyer who will make the best possible case for his client. The difference was that, once installed as the country’s most senior churchman, he had a new set of clients to serve: the church of Christ; its earthly head, the Pope; and its celestial ruler, God almighty. And so the conditions were created for the series of clashes between Becket and Henry II over the rights of the church – on such matters as the handling of criminal priests by the king’s courts, or the practice of appealing from those royal courts to the court of the Pope – that led to Becket’s flight from England and his long years of French exile. Henry used underhand tactics, robbing and expelling Becket’s relatives and giving rapacious cronies free run of the Canterbury estates. Becket fought back (when the Pope would allow him) with thunderous excommunications. The deal that was eventually patched up between them was tenuous at best; the four knights who murdered Becket soon after his return to England were acting in the spirit of Henry’s wishes, even though they did not have his explicit order to kill. John Guy’s new biography tells this story in a vigorous, matter-of-fact way, helpfully filling in much of the political background, both English and continental. While he tries to analyse the psychology of the two main characters, he is keen to avoid over-elaborate speculation; the modern notion that there was a homoerotic element to their relationship (as hinted at in the Richard Burton and Peter O’Toole film) is treated with caution, and the claim that Becket was homosexual is convincingly dismissed. Much of the emphasis is on the flawed character of Henry II, whose inability to accept reality when it conflicted with his desires was, on this account, well-nigh psychopathic. That may skew the story in Becket’s favour; but there is enough evidence here of flaws in Becket’s own character to make the reader’s sympathies veer, sometimes, the other way. Here is a man who, to protect his own career prospects, refused to visit his former patron, the old Archbishop of Canterbury, on his deathbed. Here is an experienced courtier who could commit such blunders as quarrelling with his sovereign over a furred cloak, or – more seriously – resigning from the chancellorship without consulting Henry first. John Guy is a skilful explainer of historical complexities to the general reader, and there is much to be learnt from this book. Too often, however, his prose relapses into slackness and cliché: Paris has a “vibrant social scene”, Becket gets into a “tight corner” and undergoes a “baptism of fire”, while Henry’s anger is “fuelled by the spiralling breakdown” of their friendship. This, one cannot help feeling, is an account which differs from the work of TS Eliot in more ways than one.