Tadeáš Hájek of Hájek (, ; 1 December 1525 – 1 September 1600), also known by Latinized names Thaddaeus Hagecius ab Hayek and Thaddeus Nemicus, was a naturalist and astronomer from

Bohemia Bohemia ( ; ; ) is the westernmost and largest historical region of the Czech Republic. In a narrow, geographic sense, it roughly encompasses the territories of present-day Czechia that fall within the Elbe River's drainage basin, but historic ...

. He was a personal

physician A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Med ...

of the

Holy Roman Emperor The Holy Roman Emperor, originally and officially the Emperor of the Romans (disambiguation), Emperor of the Romans (; ) during the Middle Ages, and also known as the Roman-German Emperor since the early modern period (; ), was the ruler and h ...

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 H ...

and an

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

in the

Kingdom of Bohemia The Kingdom of Bohemia (), sometimes referenced in English literature as the Czech Kingdom, was a History of the Czech lands in the High Middle Ages, medieval and History of the Czech lands, early modern monarchy in Central Europe. It was the pr ...

Biography

Tadeáš Hájek was born on 1 December 1525 in

Prague Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...

. He was the son of Šimon Hájek (–1551) from an old Prague family. He was

ennobled Nobility is a social class found in many societies that have an aristocracy. It is normally appointed by and ranked immediately below royalty. Nobility has often been an estate of the realm with many exclusive functions and characteristics. Th ...

in 1554 by

Ferdinand I of Germany Ferdinand 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 sabora Kraljevine Hrv ...

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

Holy Roman Empire The Holy Roman Empire, also known as the Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman Emperor. It developed in the Early Middle Ages, and lasted for a millennium ...

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

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

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

Bologna Bologna ( , , ; ; ) is the capital and largest city of the Emilia-Romagna region in northern Italy. It is the List of cities in Italy, seventh most populous city in Italy, with about 400,000 inhabitants and 150 different nationalities. Its M ...

and went to

Milan Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nea ...

the same year to listen to lectures by

Girolamo Cardano Gerolamo Cardano (; also Girolamo or Geronimo; ; ; 24 September 1501– 21 September 1576) was an Italian polymath whose interests and proficiencies ranged through those of mathematician, physician, biologist, physicist, chemist, astrologer, a ...

, but he soon returned to

, where he became a professor of

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

at the

Charles University of Prague Charles University (CUNI; , UK; ; ), or historically as the University of Prague (), is the largest university in the Czech Republic. It is one of the oldest universities in the world in continuous operation, the oldest university north of the ...

in 1555. He published the ''Aphorismi Metoposcopici'' in 1561, dealing with

divination Divination () is the attempt to gain insight into a question or situation by way of an occultic ritual or practice. Using various methods throughout history, diviners ascertain their interpretations of how a should proceed by reading signs, ...

and diagnosis by interpreting lines on the

forehead In human anatomy, the forehead is an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows. The bottom of the fo ...

. He triangulated the area around Prague and in 1563 co-authored a map of it, which is lost. 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 propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions of celesti ...

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

Habsburg monarchy The Habsburg monarchy, also known as Habsburg Empire, or Habsburg Realm (), was the collection of empires, kingdoms, duchies, counties and other polities (composite monarchy) that were ruled by the House of Habsburg. From the 18th century it is ...

and

Hungary Hungary is a landlocked country in Central Europe. Spanning much 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 south, Croatia and ...

during the war with the

Ottoman Empire The Ottoman Empire (), also called the Turkish Empire, was an empire, imperial realm that controlled much of Southeast Europe, West Asia, and North Africa from the 14th to early 20th centuries; it also controlled parts of southeastern Centr ...

. He published his studies of a

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

in the constellation

Cassiopeia Cassiopeia or Cassiopea may refer to: Greek mythology * Cassiopeia (mother of Andromeda), queen of Aethiopia and mother of Andromeda * Cassiopeia (wife of Phoenix), wife of Phoenix, king of Phoenicia * Cassiopeia, wife of Epaphus, king of Egy ...

in 1572. Tadeáš Hájek was in frequent scientific correspondence with the recognized astronomer

Tycho Brahe Tycho Brahe ( ; ; born Tyge Ottesen Brahe, ; 14 December 154624 October 1601), generally called Tycho for short, was a Danish astronomer of the Renaissance, known for his comprehensive and unprecedentedly accurate astronomical observations. He ...

(1546–1601) and played an important role in persuading Rudolf 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 of p ...

) to Prague. His voluminous writings in

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

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 (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its cen ...

. 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 John Dee (13 July 1527 – 1608 or 1609) was an English mathematician, astronomer, teacher, astrologer, occultist, and alchemist. He was the court astronomer for, and advisor to, Elizabeth I, and spent much of his time on alchemy, divination, ...

as a result of their common interest in

Euclid Euclid (; ; 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 geometry that largely domina ...

and

geometry Geometry (; ) is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician w ...

. He died on 1 September 1600 in Prague.

Honours

The lunar

crater A crater is a landform consisting of a hole or depression (geology), depression on a planetary surface, usually caused either by an object hitting the surface, or by geological activity on the planet. A crater has classically been described ...

'' Hagecius'' and the

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

'' 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:Hajek, Tadeas 1525 births 1600 deaths Naturalists from Bohemia 16th-century physicians Astronomers from Bohemia Scientists from Prague Academic staff of Charles University Physicians from Prague Knights of the Holy Roman Empire