A distinguished black man kneels on a riverbank before a bearded white man in robes, with the air of a prophet. What could a depiction of this scene be other than the well-known story from chapter 8 of The Acts of the Apostles? No Dutch notary of the seventeenth century hesitated in identifying the subject of a painting with this motif as the baptism by Philip of an Ethiopian official called a moor, a eunuch or a chamberlain. On the road from Jerusalem to Gaza, he becomes convinced of the div...