# Mathematician:Johannes Müller von Königsberg

## Contents

## Mathematician

Better known under his Latinized name (**Johannes Müller**) **Regiomontanus**: both surnames mean **King's mountain**.

German mathematician, astronomer, astrologer, translator, instrument maker and Catholic bishop.

Pupil of Georg von Peuerbach, whose uncompleted work he continued.

Set up a printing press at Nuremberg in 1471 -- 1472 for printing scientific works.

First publisher of such scientific literature.

Became internationally famous within his own lifetime.

## Nationality

Dutch, of German origin

## History

- Born: 6 June 1436 in Unfinden (near Königsberg), Lower Franconia (now in Bayern, Germany)
- 1447: Joined University of Leipzig to study dialectics
- 14 April 1450: Entered the University of Vienna to become pupil of Georg von Peuerbach
- 16 January 1452: Awarded a baccalaureate
- 1457: Awarded a Master's Degree (on reaching required age of 21)
- 11 November 1457: Appointed to the Arts Faculty of the University of Vienna to study under Peuerbach
- 1458: Delivered course on perspective
- 1460: Delivered course on Euclid
- 1461: Delivered course on Virgil's
*Bucolics* - 1461: Took over the work to complete
*Epytoma in Almagesti Ptolemei*started by Peuerbach - 20 November 1461: Travelled to Italy under patronage with Cardinal Bessarion
- 1461 to 1465: Based in Rome as a member of Bessarion's extended household
- Summer 1462: At Viterbo with Bessarion
- Autumn 1462: Accompanied Bessarion as far as Venice
- 1462: found an incomplete copy of Diophantus's
*Arithmetica* - 5 July 1463: Left Rome
- Spring 1464: Lectured at the University of Padua in the Venetian Republic
- 21 April 1464: Observed the total eclipse of the moon
- August 1464: Returned to Rome after death of the Pope Pius II
- 19 June 1465: Made an observation at Viterbo
- 1467: In Hungary, having accepted an appointment from the King to the Royal Library in Buda
- c. 1471: Moved to Nuremberg
- 1471-1472: in he set up a printing press in his own house in Nuremberg
- 1476: summoned to Rome by Pope Sixtus IV to advise on calendar reform
- Died: 6 July 1476 in Rome, Italy of unknown causes (probably plague, but rumoured to have been poisoned)

## Theorems

- Regiomontanus' Angle Maximization Problem
- Law of Sines for Spherical Triangles
- Law of Cosines for Spherical Triangles

Results named for **Johannes Müller von Königsberg** can be found here.

## Publications

- 1462:
*Epytoma in Almagesti Ptolemei*(begun by Georg von Peuerbach) - 1463: a translation of
*Arithmetica*by Diophantus (incomplete) - 1464:
*De Triangulis Omnimodus*, one of the first textbooks on trigonometry - 1467:
*Tabulae directionum*(Tables of Directions), a manual for calculating astrological houses - 1474:
*Kalendarium* - 1474:
*Ephemerides*

*Algorithmus Demonstratus**Introductory Discourse on All the Mathematical Disciplines**Theoricae novae Planetarum**The Defence of Theon against George of Trebizond**Scipta*

## Also known as

**Johannes Molitoris de Künigsperg**(**Molitoris**is a Latin form of**Müller**)**Johannes Germanus**(Johann the German)**Johannes Francus**(Johannes from Franconia)**Johann von Künigsperg**(Johann from Königsberg)**Joannes de Monte Regio**(used by Gassendi in his biography)**Regiomontus**(possibly erroneously)- At least one online source has
**Regionontanus**, which is clearly erroneous.

## Sources

- John J. O'Connor and Edmund F. Robertson: "Johannes Müller von Königsberg": MacTutor History of Mathematics archive

- 2008: Ian Stewart:
*Taming the Infinite*... (previous) ... (next): Chapter $5$: Eternal Triangles