Today is also the 533 rd. anniversary of the death of the 15th century’s most important mathematician and astronomer, John Miller. Now anybody reading the previous sentence is probably thinking who the f##k is John Miller? Shall we try with his name in the original German, Johannes Müller, is that any better? Probably not, how about Regiomontanus? AH! Now, you’ve probably heard of him. Johannes Müller is the real name of Regiomontanus who came from the town of Königsberg (English; Kings-Mountain) in Lower Franconia, not to be confused with the much more famous Königsberg in East Prussia, now known as Kaliningrad and once home to Immanuel Kant. Old reference books quite often claim that Regiomontanus came from the Prussian Königsberg to the annoyance of all patriotic Franconians.
The name Regiomontanus is a toponym that is a name adopted by a scholar or author based on a place name, usually his place of birth but sometimes his place of residence. Toponyms were very common in the Middle Ages, famous examples being Aquinas and da Vinci. Now the toponym Regiomontanus is not without controversy, as can be seen from this somewhat outraged comment from a Wikipedia editor:
It is not true that Regiomontanus came to be called after the Latin name of his place of birth, Königsberg, Bavaria, posthumously. In his time, it was common for scholars to Latinize their names in their publication.
As I have already pointed out the editor’s second statement is correct although, as I said many authors Latinised the names of their birthplaces rather than their family names. The problem is the first statement, which is unfortunately false. As a student Herr Müller did indeed Latinise his family name and was matriculated under the mane Molitoris. In later letters, when he was on his peregrinations through Italy and Hungary, he is often referred to as Ioannes Germanicus i.e. John the German. When he started publishing he used the toponym Ioannes de Monte Regio. As far as can be ascertained he never used the name Regiomontanus. The earliest know incident of his being named Regiomontanus is in a text of Phillip Melanchthon’s from 1531, 55 years after his death.
Nowadays he is universally known as Regiomontanus and it would be foolish for any historian to try and change that, but any good historian should be aware of the falseness of this name.