Vincent van Gogh wanted to create portraits that would “appear as revelations to people in a hundred years' time”. He believed them to be a means of showing “the soul of the model.” Self-Portrait Dedicated to Paul Gauguin, shown here, was painted in 1888, two years before van Gogh's death. (From Van Gogh Face to Face: The Portraits by Roland Dorn et al.; Thames & Hudson, £32, $50.)