the acquaintance of the leading Italian mathematicians of the age such as Giovanni Bianchini and Paolo dal Pozzo Toscanelli who had also been friends of Peuerbach during his prolonged stay in Italy more than twenty years earlier. In 1467, he went to work for János Vitéz, archbishop of Esztergom. There he calculated extensive astronomical tables and built astronomical instruments. Next he went to Buda, and the court of Matthias Corvinus of Hungary, for whom he built an astrolabe, and where he collated Greek manuscripts for a handsome salary. The trigonometric tables that he created while living in Hungary, his Tabulae directionum profectionumque (printed posthum., 1490), were designed for astrology, including finding astrological houses. The Tabulae also contained several tangent tables. In 1471 Regiomontanus moved to the Free City of Nuremberg, in Franconia, then one of the Empire's important seats of learning, publication, commerce and art, where he worked with the humanist and merchant Bernhard Walther. Here he founded the world's first scientific printing press, and in 1472 he published the first printed astronomical textbook, the Theoricae novae Planetarum of his teacher Georg von Peurbach. Regiomontanus and Bernhard Walther observed the comet of 1472. Regiomontanus tried to estimate its distance from Earth, using the angle of parallax. According to David A. Seargeant: The 1472 comet was visible from Christmas Day 1471 to 1 March 1472 (Julian Calendar), a total of 59 days. In 1475, Regiomontanus was called to Rome by Pope Sixtus IV on to work on the planned calendar reform. Sixtus promised substantial rewards, including the title of bishop of Regensburg, it is unlikely that he was actually appointed to the role. On his way to Rome, stopping in Venice, he commissioned the publication of his Calendarium with Erhard Ratdolt (printed in 1476). Regiomontanus reached Rome, but he died there after only a few months, in his 41st year, on 6 July 1476. According to a rumor repeated by Gassendi in his Regiomontanus biography, he was poisoned by relatives of George of Trebizond whom he had criticized in his writing; it is however considered more likely that he died from the plague. Work During his time in Italy he completed Peuerbach's Almagest abridgement, Epytoma in almagesti Ptolemei. In 1464, he completed De triangulis omnimodis ("On Triangles of All Kinds"). De triangulis omnimodis was one of the first textbooks presenting the current state of trigonometry and included lists of questions for