Dante in Love, By AN Wilson

AN Wilson's new book is designed to help the many readers who have hitherto been "prepared to take it on trust that Dante is a great poet, but... leave him as one of the great unreads". This handsome, reassuringly substantial volume is no set of Pass Notes. Nor is it simple literary biography. Instead, Wilson explores the motivation and thought underlying the Divine Comedy. Since, as he points out, one of the difficulties this poem presents for the contemporary reader is Dante's range of allusion, his is complex task: "The greatest of all European poems cannot be understood unless you familiarise yourself with the Europe out of which it came."

Moving broadly chronologically, Dante in Love reveals a "back story" that is rich in both biographical detail and political history. Indeed, it shows how these are inseparable elements of a life spent in the public sphere of a medieval Italian city-state. Dante Alighieri was, after all, betrothed at the age of 11 to secure his father's alliance with one of the most powerful families in Florence.

The Donati were leaders of the Guelf faction, then in the ascendancy. Gemma Donati would indeed become Dante's wife and the mother of his children, even though we're more accustomed to associating the poet with the figure of Beatrice Portinari. The Guelfs' traditional enemies were the Ghibellines; but when wider European political forces divided the Guelfs into "Black" and "White" factions it was Dante's own in-law Corso Donati who in 1301 seized control of Florence, exiling the poet along with 600 other Whites. When Dante died 20 years later, still in exile though settled in Ravenna, it was of malaria contracted in the Venetian swamps after a diplomatic mission undertaken on behalf of his new home.

As ever, Wilson writes elegantly and so clearly that the least historically-minded reader can follow this story of shifting fortunes. But this isn't popular history; it's a book about a book. As with all poetry, the devil of the Divine Comedy is in its detail.

Wilson shows just how intimately-lived political experience informed the work, creating an intricate cross-patterning that binds the poem together. Canto XXIV of Purgatorio portrays Corso Donati dealt, after death, the traditional punishment for a traitor: "dragged by the tail of a beast,/ towards the valley where sins are not forgiven". Personal references sit side by side with contemporary events. Canto XX records the fatal imprisonment of Pope Boniface by the French army: "I see the Fleur-de-lis enter Anagni/ and in his vicar Christ made prisoner./ I see the gall and vinegar renewed;/ I see Him being mocked a second time,/ Killed once again between the living thieves."

The passage is from Mark Musa's 1973 edition. One of the pleasures of the book is the way Wilson uses a writer's ear to select from a variety of different translations, occasionally supplying his own versions. Part of what makes these lines so vivid is their use of transformative Christian symbolism. The Divine Comedy is much more than mere revenge-fantasy, or an escapist ideal of eventual justice. As Wilson points out, Dante's work also has theological significance. In the 13th century, doctrinal schema were not yet fully fixed, and the Comedy "was destined, almost literally, to put Purgatory on the map". Several of the colour plates illustrate the medieval cosmology from which this new, tripartite structure emerged.

A third dimension of the Comedy is Dante's sheer poetic ear and gift. This might require a different, perhaps more conventional, kind of book to do it justice. Nevertheless, we glimpse the gifted author of love lyrics and learn how revolutionary his synthesis of Christian and classical iconography was, and how he developed his signature terza rima rhyme-scheme, which Wilson sees as "Trinitarian". Such attention to the work's poetic character is unsurprising since, as he tells us in an introductory chapter, Wilson's search for ways to read Dante started when he was a scholar of medieval literature at Oxford.

Not surprisingly, he has a theory of his own to propound – and it gives his book its title. According to Wilson, Beatrice, the muse of the Vita Nuova and redemptive ideal of Paradiso, represented for Dante not just a simple love-object but the principle of divine instantiation: therefore, of the divine. Since love and childhood crushes – Dante was eight when he first saw Beatrice – are surely often just this intense, the possibility seems not so much new as a question of degree, and evidence of the transformative work of poetry. Dante in Love is not just a thoroughly readable, illuminating story but, with its fascinating store of detail, a practical reference volume. It is a worthy vade mecum with which to explore Dante's masterpiece itself.

Fiona Sampson's edition of Percy Bysshe Shelley (Faber) appears in July