Martin Gayford feels that biographies generally fail to convey 'a sense of what it would be like to meet the subject face to face'. In his account of one of the most famous and intimately documented episodes in the history of art he attempts to put us 'in the same room' as his subjects – even 'inside their heads'. But looking at the extraordinary self-portraits they exchanged (before Gauguin finally showed up at Van Gogh's anxiously prepared Yellow House on 23 October 1888), it is difficult to avoid the feeling that one would distinctly rather not be in the same room as this murderous-looking pair. Van Gogh, portraying himself, he says, 'in the character of a simple bonze worshipping the eternal Buddha', comes across as more psychopath than monk, while Gauguin, modelling himself on Jean Valjean, Victor Hugo's outcast hero from Les Misérables, is a sinister villain, leering slyly from the corner of the canvas. As for 'inside their heads' – in a covering letter sent with the Les Misérables self-portrait, Gauguin wrote:

Passionate blood suffuses the face as it does a creature in rut, and the eyes are enveloped by tones as red as the fire of a forge, which indicate the inspiration like molten lava which fills the soul of painters like us.

It sounds in this passage as if Gauguin aspired to madness for creative purposes – while poor Van Gogh, his head fizzing with ideas like a pressure-cooker, was trying to cling on to his sanity.

There would have been more prosaic reasons, too,