Portrait of the artist: Lucian Freud's Frank Auerbach

The genius of Lucian Freud shone out at the end of the 20th century. Freud exemplifies the fact that British artists have often found their most original insights in the most eccentric places. At a time when the avant garde ruled, he painted in the tradition of Constable and Gainsborough – but where in other artists this might be a recipe for irrelevance, in Freud it released the deepest, most intense painting of recent times. Here he portrays another remarkable British painter, Frank Auerbach, in a moving, arresting image of thought Illustration: Courtesy of Lucian Freud archives