Tadeáš Hájek z Hájku () (1 December 1525 in

Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and List of cities in the Czech Republic, largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 milli ...

– 1 September 1600 in Prague), also known as Tadeáš Hájek of Hájek, Thaddaeus Hagecius ab Hayek or Thaddeus Nemicus, was a

Czech Czech may refer to: * Anything from or related to the Czech Republic, a country in Europe ** Czech language ** Czechs, the people of the area ** Czech culture ** Czech cuisine * One of three mythical brothers, Lech, Czech, and Rus' Places * Czech, ...

naturalist, personal

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

of the Holy Roman Emperor

Rudolph II Rudolf II (18 July 1552 – 20 January 1612) was Holy Roman Emperor (1576–1612), King of Hungary and Croatia (as Rudolf I, 1572–1608), King of Bohemia (1575–1608/1611) and Archduke of Austria (1576–1608). He was a member of the Ho ...

and an

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

in the

Kingdom of Bohemia The Kingdom of Bohemia ( cs, České království),; la, link=no, Regnum Bohemiae sometimes in English literature referred to as the Czech Kingdom, was a medieval and early modern monarchy in Central Europe, the predecessor of the modern Czec ...

Biography

Tadeáš Hájek was the son of Šimon Hájek (ca. 1485–1551) from an old Prague family. He was ennobled in 1554 by

Ferdinand I of Germany Ferdinand I ( es, Fernando I; 10 March 1503 – 25 July 1564) was Holy Roman Emperor from 1556, King of Bohemia, Hungary, and Croatia from 1526, and Archduke of Austria from 1521 until his death in 1564.Milan Kruhek: Cetin, grad izbornog sabor ...

, knighted in 1571 by Maximilian II, later made knight of the

Holy Roman Empire The Holy Roman Empire was a political entity in Western, Central, and Southern Europe that developed during the Early Middle Ages and continued until its dissolution in 1806 during the Napoleonic Wars. From the accession of Otto I in 962 ...

Rudolf II Rudolf II (18 July 1552 – 20 January 1612) was Holy Roman Emperor (1576–1612), King of Hungary and Croatia (as Rudolf I, 1572–1608), King of Bohemia (1575–1608/1611) and Archduke of Austria (1576–1608). He was a member of the Hous ...

. He had three wives, three sons, and one daughter. In 1548–1549, he studied medicine and astronomy in

Vienna en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...

and graduated in 1550, receiving his Masters "''in artibus''" in 1551. In 1554 he studied medicine in

Bologna Bologna (, , ; egl, label=Emilian language, Emilian, Bulåggna ; lat, Bononia) is the capital and largest city of the Emilia-Romagna region in Northern Italy. It is the seventh most populous city in Italy with about 400,000 inhabitants and 1 ...

and went to

Milan Milan ( , , Lombard: ; it, Milano ) is a city in northern Italy, capital of Lombardy, and the second-most populous city proper in Italy after Rome. The city proper has a population of about 1.4 million, while its metropolitan city h ...

the same year to listen to lectures by

Girolamo Cardano Gerolamo Cardano (; also Girolamo or Geronimo; french: link=no, Jérôme Cardan; la, Hieronymus Cardanus; 24 September 1501– 21 September 1576) was an Italian polymath, whose interests and proficiencies ranged through those of mathematician, ...

, but he soon returned to

, where he became a professor of mathematics at the

Charles University of Prague ) , image_name = Carolinum_Logo.svg , image_size = 200px , established = , type = Public, Ancient , budget = 8.9 billion CZK , rector = Milena Králíčková , faculty = 4,057 , administrative_staff = 4,026 , students = 51,438 , under ...

in 1555. He published the ''Aphorismi Metoposcopici'' in 1561, dealing with divination and diagnosis by interpreting lines on the forehead. He triangulated the area around Prague and co-authored a map of it in 1563; the map is unfortunately lost now. In 1564 he received the Emperor's privilege stating that no

astrological Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Dif ...

prognostication could be printed in Prague before he had seen and approved it. In 1566–1570, he served as an army doctor in

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

and

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the ...

during the war with the

Ottoman Empire The Ottoman Empire, * ; is an archaic version. The definite article forms and were synonymous * and el, Оθωμανική Αυτοκρατορία, Othōmanikē Avtokratoria, label=none * info page on book at Martin Luther University) ...

. He published his studies of a supernova in the constellation Cassiopeia in 1572. Tadeáš Hájek was in frequent scientific correspondence with the recognized astronomer

Tycho Brahe Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was ...

(1546–1601) and played an important role in persuading Rudolph II to invite Brahe (and later

Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws o ...

) to Prague. His voluminous writings in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

were mostly concerned with astronomy and many regarded him as the greatest astronomer of his time. Besides his work, Tadeáš Hájek eagerly collected manuscripts, especially those by

Copernicus Nicolaus Copernicus (; pl, Mikołaj Kopernik; gml, Niklas Koppernigk, german: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance polymath, active as a mathematician, astronomer, and Catholic canon, who formulated ...

. Throughout his life he also published numerous astrological prognostics in Czech and that is why he was until recently viewed as an "occultist" rather than a great scientist. He corresponded with John Dee as a result of their common interest in

Euclid Euclid (; grc-gre, Εὐκλείδης; BC) was an ancient Greek mathematician active as a geometer and logician. Considered the "father of geometry", he is chiefly known for the '' Elements'' treatise, which established the foundations of ...

and

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ...

. The lunar crater '' Hagecius'' and the asteroid '' 1995 Hajek'' are named in his honour.

Works

References

* Thaddaeus Hagecius ab Hayck: ''Dialexis de novae et prius incognitae stellae inusitatae magnitudinis & splendidissimi luminis apparitione, & de eiusdem stellae vero loco constituendo'', Frankfurt/Main, 1574, edit. Zdenek Horsky, Prague, 196

* Z. Horský: ''Thaddaeus Hagecius (1525 - 1600)'', Ríse hvezd, Vol. 56, p. 228 - 229., 197

{{DEFAULTSORT:Hagecius 1525 births 1600 deaths Czech astronomers Scientists from Prague Academic staff of Charles University Physicians from Prague