There is a vogue these days for biographies of minor, peripheral characters who lived on the margins of literary greatness: Tennyson's wife, for instance, or Dickens' mistress.

This new biography of Lord Alfred Douglas, the son of the Marquess of Queensbury and, most scandalously, the lover of Oscar Wilde, has attracted huge attention because of the age of the biographer. Douglas Murray began writing it at 17, and he is only 20 now. It is an astonishing achievement: mature, considered, fluently written and richly detailed. Bosie's youth was the epitome of the 1890s,"greenery-yallery" decadence, but unlike his lover and mentor, the brilliant, doomed Wilde, Bosie lived on until 1945, becoming increasingly religious, repentant about his past (as Wilde never was), and finally a recluse.

On one key issue, however, Murray seems seriously off-message: he argues that Bosie was a major literary figure in his own right, and that the value of his poetry has been seriously underrated. "He was a poet not just of the 90s but one who would endure the 20th century and produce a poem that would echo as a work of searing faith and a testament to spiritual renewal." Er ... no. The poem Murray alludes to is "In Excelsis", Bosie's riposte to Wilde's work "De Profundis".

But it is tiresomely self-absorbed, antiquated, and unimaginative, a prolonged whinge about the lot of the misunderstood genius. Nevertheless, Bosie's story is still worth telling, even if his poetic reputation is not worth defending, and Murray tells it extremely well. --Christopher Hart