The aberration of starlight seems to be one of the simplest phenomena of astronomical observation. However, the story of misunderstandings is long and lasts till now. It is nearly forgotten that the problem of stellar aberration was the cornerstone of the development and the acceptance of relativity. In addition, there seems to be no essentially final point in the discussion of its interpretation, the discussion seems to merely be given up. Of course, with the correct relativistic formulas, there is no need of interpretation any more. The price of this consists in the many incorrect descriptions and interpretations that arise if a textbook tries to explain in words the mere formulas. We try to review the problems discussed in the last three centuries and to give them a final, i.e. geometrical form. We are convinced that this teaches a lot about the geometry of the space-time union.