This paper focuses on Paul Klee's painting, 'Angelus Novus' (1920), and the interpretation of that painting by Walter Benjamin, who owned it, in his celebrated theses 'On the Concept of History' (1940). Benjamin's interpretation was a kind of parable: he called it the angel of history. The paper proposes that the subject of the painting, the angel, is a kind of witness; that the work of art, the painting, is also a kind of witness; and that its provenance has added a rich seam of witnessing, over the last century.