Today is the day of death of two of my most prominent local scientists. Georg Simon Ohm who was born 17th March 1789 in Erlangen died 6th July 1854 in Munich. Johannes Müller, better known as Regiomontanus, was born in Königsberg in Lower Franconia 6th June 1436 and having spent the last five years of his life in Nürnberg died in Rome 6th July 1476. You can find these dates in almost all standard sources so everything appears simple and in order. However at least in the case of Regiomontanus appearances are deceptive; what we have here is a date of death that is anything but certain.
Like many Renaissance figures Regiomontanus’ early life is very sketchy but from the 15th April 1450, when he first matriculated at the University of Vienna, onwards his life in incredibly well documented through university matriculation lists, letters, official documents and his observation logs as an observational astronomer. There is a period of about eighteen months from 1465 to 1467 where he disappeared from the radar screen but otherwise we can say exactly where he was until the July 28th 1475 when he simply disappears out of the world. On July 28th he made the last entry in his observation log in Nürnberg and on August 2nd his partner Bernhard Walther made the next entry and it is assumed that he left Nürnberg between these two dates. Later in 1476 Hartmann Schedel, author of the legendary Nuremberg Chronicle, recorded in his diary that Regiomontanus had been called to Rome by the Pope to work on a calendar reform and that he had died there in June 1476; he had originally written July then crossed it out and written June. He does give a date for the death. There is however no Papal letter or commission to confirm his call to Rome
Thomas Gechauff (1488 – 1551), better known as Venatorius, who edited the first printed edition of the works of Archimedes in 1544, claimed that Regiomontanus had died about 8th July 1476 and Rheticus (1514 – 1574) claimed that 8th July as date of death came from Regiomontanus’ executers. In 1549 Erasmus Reinhold simply stated that he had died in 1476.
In 1654 Pierre Gassendi (1592 – 1655) published the first biography of Regiomontanus in which he stated that he had died 6th July 1476. For 300 years Gassendi’s remained the only biography and so his almost certainly incorrect date of death established itself as the official version. Next time you see the date of death of a scientist who died in the Renaissance don’t take it as gospel there’s a good chance it’s just as dubious as that of Regiomontanus.