Sins and secrets of the medieval kings Henry VIII's graffiti on an illuminated page feature in a future episode of Dr Nina Ramirez's BBC Four series. "If you remember my love in your prayers," the king wrote to his future wife, Anne Boleyn, "as strongly as I adore you, I shall hardly be forgotten." There are two odd things about this message. One is that it is in French. I suspect it was a sort of conventional love memento, like a verse in a Valentine's card. More strangely, the message appears below a picture of the "Man of Sorrows," an image of Jesus, wearing only a loincloth, with his body covered with the bloody wounds of his scourging. Before him lies an open tomb. It was painted, with great skill, by the illuminator to evoke pious feelings of sympathy for the Saviour whom sins had wounded. So it's not at all a conventional Valentine's image. Anne's reply is also in a pre-packed couplet: "Be [by] daily prove you shall me fynde / To be both loving and kynd." This is written under a picture of the angel Gabriel announcing to Mary that she is to be the mother of Jesus. To father a son was Henry's strong ambition. Could the book have been a New Year's gift from Henry to the woman he had fallen in love with? After his signature, the King has written "January" - in those days, the traditional time to exchange gifts. This mixture of sacred and profane, of sex and prayer, might not have seemed so jarring then as at it does now. Another king's prayer book was on show at the V&A in 2006 and it showed a naked Bathsheba bathing, with King David looking on lasciviously. The book had belonged to Louis XII of France. At the time of the exhibition, Thomas Kren, an expert at the J Paul Getty Museum, commented: "Louis's seductive miniature, showing a voluptuous Bathsheba at her bath, must have given him great pleasure." Possibly, but he must surely have remembered David's great psalm of repentance (the 51st), which the illumination illustrated: "A clean heart create for me, O God." We need to do more than simply project our own reactions on to the books" owners. The books seen on television were "rarely if ever seen by the average person," Dr McKendrick notes. If they saw them, they'd have made nothing of the script. But isn't it as true of us today? We can hardly make out the letters, let alone understand the Latin. That's one reason that crowds do not routinely gather round the permanent displays at the British Library. We need a guide, like Dr Ramirez. But more than making out the words, it's important to understand what made those kings, queens and abbots shape such precious and often puzzling images. I'm looking forward to next week's episode. Illuminations: The Private Lives of Medieval Kings is on BBC4 next Monday at 9pm