For William Butler Yeats, Dante Alighieri was "the chief imagination of Christendom." For T. S. Eliot, he was of supreme importance, both as poet and philosopher. Coleridge championed his introduction to an English readership. Tennyson based his poem "Ulysses" on lines from the Inferno. Byron chastised an "Ungrateful Florence" for exiling Dante. The Divine Comedy resonates across five hundred years of our literary canon.

In Dante in Love, A. N. Wilson presents a glittering study of an artist and his world, arguing that without an understanding of medieval...