Astronomer. Born Tyge Otteson Brahe the eldest son of Beate Clausdatter Bille and Otte Tygesson, a Danish nobleman and landowner, in Knutstorp, Skåne (present day Sweden). At about age two, his childless aunt and uncle, Inger Oxe and Jørgen Brahe appropriated the boy from his home, and with his parents eventual permission, raised him as their own son. In April 1559, he enrolled in the University of Copenhagen where he was first introduced to astronomy. In February 1562, he traveled to the University of Leipzig to further his education. He began making astronomical observations, and by August 1563, was keeping a log of the observations. The second observation he recorded was a conjunction of Jupiter and Saturn which proved significant - neither tables based on Copernicus' nor on Ptolemy's calculations had given the correct date for the conjunction. He returned home in May 1565 shortly before his uncle's death, and his subsequent return to his parents house. In 1566, he returned to Germany and attended the universities at Basal, Wittenberg, and Rostock. While at Rostock he participated in a drunken duel with another Danish student which left him with a deep scar to his forehead and a badly damaged nose. For the remained of his life he wore a brass prosthetic to conceal the injury to the bridge of his nose. In 1572, he observed a new star in Cassiopeia and published 'De Nova et Nullius Aevi Memoria Prius Visa Stella' (On the New and Never Previously Seen Star) the following year. In 1574, he gave a series of talks on astronomy at the University of Copenhagen. In September 1574, he visited Kassel where Wilhelm IV of Hessen-Kassel had founded an observatory more than a decade previously. He returned to Denmark in 1575 where King Frederick II offered to fund an observatory on the island of Hven (present day Ven) in Copenhagen Sound. Called Uraniborg, Brahe built what was regarded as the finest observatory in Europe. In 1584, he outgrew Uraniborg and built a second observatory, Stjerneborg. Initially convinced of Copernicus' Sun centered model of the solar system, his observable evidence eventually led him to believe either the Earth was fixed, or the scale of the universe was incomprehensibly immense; he opted for the first theory: a stationary Earth around which the Moon and Sun revolved while the other planets revolved round the Sun. The precise astronomical data that he collected over his lifetime eventually led to the development of the three laws of planetary motion. By the time he was in his fifties, his behavior became increasingly harsh and arrogant, leading to a falling out with King Christian IV. In 1597, he left Denmark. He eventually settled in Prague where in 1599 he was appointed Imperial Mathematician to the Holy Roman Emperor, Rudolph II. His major publications included 'De Mundi Aetherei Recentioribus Phaenomenis' (Concerning New Phenomena in the Ethereal World; 1588); 'Astronomiae Instauratae Mechanica' (Instruments for the Restored Astronomy; 1598); 'Astronomiae Instauratae Progymnasmata' (Introductory Exercises Toward a Restored Astronomy; 1602). He hired Johannes Kepler as his assistant in mathematical calculations. Brahe's insistence on accuracy and his design of instruments, which he regularly calibrated to check their accuracy, were great contributions to the field. He cataloged more than 1,000 new stars. He revolutionized astronomical instrumentation. He was the first astronomer to make corrections for atmospheric refraction, and his observations were instrumental in establishing the fact that the heavens were not immutable as Aristotle had argued and was then still largely believed, but changeable. He was the last of the noted astronomers to work without a telescope. He succumbed to what was probably either kidney failure or a bladder infection at the age of 54. His body was exhumed once in 1901 and again in 2010 for analysis, the results of which conclusively put to rest theories of anything other than a natural death.