Most people know me by the name Regiomontanus, from the Latin name for my home town of Konigsberg.
As a mathematician and an astronomer, I was deeply involve in the translation and republishing of the original Greek texts (such as Ptolemy's Almagest).
My most famous work, On Triangles of All Kinds, summarized everything that was known about plane and spherical triangles, and thereby essentially established trigonometry as a branch of mathematics separate from astronomy.
As then operator of both an observatory and a private printing press, I published popular calendars in both German and Latin.
In 1475, Pope Sextus IV invited me to Rome to give him advice on coordinating calendar dates with astronomical events....but I died mysteriously on my arrival.
Johannes Muller (1436-1476)