Georg Peurbach (Also spelled Georg Purbach) was born May 30, 1423 in Peuerbach, Austria. He studied at the University of Vienna, graduating in 1446 and receiving a Master's Degree in 1453. He then travelled through Europe lecturing on astronomy, before returning to the University of Vienna to teach Mathematics and Astronomy. He was also appointed court astronomer by King Ladislaus of Hungary in 1454.
While teaching in Vienna he discovered a promising young student, who was to become his partner in matters astronomical, Johann Müller (who was usually know by the name of Regiomontanus, altho it does seem that he used this name himself). Together, they studied the work of Ptolemy. With the aid of Cardinal Bessarion (who was trying to introduce the Almagest to the West), they worked on bringing the works of Ptolemy to the attention to the modern scientific world, rewriting some works to be more easily read.
Peurbach's principle work was Theoricae Novae Planetarum, a attempt to refine the Ptolemaic system. He believed that the planets were in solid crystalline spheres and that their motions were controlled by the sun. The work itself isn't anything special, but in pursuing his goal he was the first European to make use of trigonometry, and wrote a work on the computation of sines and chords (Tractatus super pro positiones Ptolemaei de sinubus et chordis, 1541).
Peurbach also observed and reported on Halley's comet in June 1456, created tables of eclipse calculations (Tabulae Ecclipsium), observed and reported on Lunar eclipse in September 1457, and wrote an elementary textbook on practical calculations entitled Algorismus, which was a big seller.
Peurbach invented some astronomical instruments worthy of note: the Geometrical Square to measure altitudes; Jacob's Staff, which was a modification of Ptolemy's Triquetrum; and the Regula for measuring the altitudes of the Sun and Moon. None of these were very precise.
All said, Peurbach's largest contribution to astronomy was probably refining the Ptolemaic system to such a point that it was obvious that it wasn't actually true (although he never questioned its validity), and paving the way for Copernicus.
Peurbach died April 8, 1461 in Vienna, Austria