Die blaue Sonne und der Einzug der Braut

Verschränkte Interpretationen eines atmosphärischen Phänomens während des Einritts der Ippolita Maria Sforza in Neapel im September 1465

Abstract

The entry of the Milanese prince’s daughter Ippolita Maria Sforza into Naples on September 14, 1465, on the occasion of her marriage to King Ferdinand’s son, is remarkable above all for an atmospheric-optical anomaly: the sun turned blue during those days and changed to other colours as well. This phenomenon is carefully ob­served and commented on by contemporaries, but hardly interpreted. The blue sun could be seen not only in Naples but in large parts of Europe, as numerous sources from the Aegean to northern Germany show. Three possibili­ties suggest themselves as factual explanations: a large volcanic eruption that released sulphur aerosols into the atmosphere, large forest fires, or Saharan dust storms; the volcanic scenario is the most likely, although so far no consensus can be established between data from ice core research, dendroclimatology, and historical research. It is interesting that the interpretative possibilities of 15th-century contemporaries are overwhelmed by a pheno­menon for which there are no biblical, historiographical, or natural-philosophical explanations available. Two epigrams of humanist poets at the court of the Neapolitan king and a courtly panegyrist, who want to reconcile the blue sun with the arrival of the educated princess, find in the reception of antiquity of the 15th century and in a creative interpretation of conventional wisdom on ce­lestial signs the appropriate framework to give meaning to what they could observe and to interpret the event in favour of Ippolita Maria Sforza.