Half a century after it was first published in 1973, Portrait of a Marriage still delivers a powerful depth charge, still intrigues and amazes in equal measure. The story it tells, of a marriage made all the stronger by the centrifugal forces of bisexual love affairs forcing it apart, is profoundly moving, and in Nigel Nicolson’s graceful telling, as relevant now as ever. We live in an age of soundbites, where complex lives are often reduced to simplistic labels – Vita Sackville-West? Ah, yes, the gardener, the lover of Virginia Woolf, the inspiration for Orlando – and need to be reminded of the fire and passion, the agony and ecstasy, that combined in the making of two such singular lives and one such singular marriage.