Gregory Choniades
Encyclopedia
Gregory Choniades (died 1302) was a Byzantine Greek
Byzantine Greeks
Byzantine Greeks or Byzantines is a conventional term used by modern historians to refer to the medieval Greek or Hellenised citizens of the Byzantine Empire, centered mainly in Constantinople, the southern Balkans, the Greek islands, Asia Minor , Cyprus and the large urban centres of the Near East...

 astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

. He travelled to Persia where he learnt Persian mathematical and astronomical science which he introduced into Byzantium
Byzantium
Byzantium was an ancient Greek city, founded by Greek colonists from Megara in 667 BC and named after their king Byzas . The name Byzantium is a Latinization of the original name Byzantion...

 upon return from Persia and founded an astronomical academy
Academy
An academy is an institution of higher learning, research, or honorary membership.The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. In the western world academia is the...

 at Trebizond
Empire of Trebizond
The Empire of Trebizond, founded in April 1204, was one of three Byzantine successor states of the Byzantine Empire. However, the creation of the Empire of Trebizond was not directly related to the capture of Constantinople by the Fourth Crusade, rather it had broken away from the Byzantine Empire...

. Choniades also served as Orthodox Bishop
Greek Orthodox Church
The Greek Orthodox Church is the body of several churches within the larger communion of Eastern Orthodox Christianity sharing a common cultural tradition whose liturgy is also traditionally conducted in Koine Greek, the original language of the New Testament...

 in Tabriz
Tabriz
Tabriz is the fourth largest city and one of the historical capitals of Iran and the capital of East Azerbaijan Province. Situated at an altitude of 1,350 meters at the junction of the Quri River and Aji River, it was the second largest city in Iran until the late 1960s, one of its former...

.

Information about Choniades survives from some contemporary sources. In 1347, George Chrysococces (Chrysococcis) writes that "a certain Chioniades, who had been raised in Constantinople
Constantinople
Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

, fell in love with mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 and other sciences. After he had mastered medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

, he wished to study astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

; he was informed that, in order to satisfy his desire, he would have to go to Persia
History of Iran
The history of Iran has been intertwined with the history of a larger historical region, comprising the area from the Danube River in the west to the Indus River and Jaxartes in the east and from the Caucasus, Caspian Sea, and Aral Sea in the north to the Persian Gulf and the Gulf of Oman and Egypt...

. He traveled to Trebizond, where he was given some assistance by the Emperor Alexios II of Trebizond
Alexios II of Trebizond
Alexios II Megas Komnenos or Alexius II , was Emperor of Trebizond from 1297 to 1330. He was the elder son of John II and Eudokia Palaiologina, and also used the name Palaiologos.- Life :...

, and thence proceeded to Persia itself, where he persuaded yet another Emperor to aid him. He eventually learned all that he wished to know, and returned to Trebizond, bearing away from Persia a number of astronomical texts which he translated
Translation
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...

 into Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

."

Sixteen of Choniades' letters have survived, which confirm that he received assistance from Alexius II and traveled to Persia. Choniades translated a number of Arabic
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...

 and Persian
Persian language
Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...

 works on mathematics
Islamic mathematics
In the history of mathematics, mathematics in medieval Islam, often termed Islamic mathematics or Arabic mathematics, covers the body of mathematics preserved and developed under the Islamic civilization between circa 622 and 1600...

 and astronomy
Islamic astronomy
Islamic astronomy or Arabic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age , and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and...

, including the astronomical tables of his teacher Shams ad-Din al-Bukhari, who had worked at the famous Maragheh observatory
Maragheh observatory
Maragheh observatory is an astronomical observatory which was established in 1259 CE by Nasir al-Din al-Tusi, an Iranian scientist and astronomer...

 under the polymath Nasir al-Din al-Tusi
Nasir al-Din al-Tusi
Khawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...

. Choniades played an important role in transmitting several innovations from the Islamic world to Europe. These include the introduction of the universal latitude-independent astrolabe
Astrolabe
An astrolabe is an elaborate inclinometer, historically used by astronomers, navigators, and astrologers. Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and longitude, surveying, triangulation, and to...

 to Europe and a Greek description of the Tusi-couple
Tusi-couple
The Tusi-couple is a mathematical device in which a small circle rotates inside a larger circle twice the diameter of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth in linear motion along a diameter of the larger...

, which would later have an influence on Copernican heliocentrism
Copernican heliocentrism
Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform...

. Choniades also translated several Zij
Zij
Zīj is the generic name applied to Islamic astronomical books that tabulate parameters used for astronomical calculations of the positions of the Sun, Moon, stars, and planets. The name is derived from the Middle Persian term zih or zīg, meaning cord...

treatises into Greek, including the Persian Zij-i Ilkhani
Zij-i Ilkhani
Zīj-i Īlkhānī or Ilkhanic Tables is a Zij book with astronomical tables of planetary movements. It was compiled by the Persian astronomer Nasir al-Din al-Tusi in collaboration with his research team of astronomers at the Maragha observatory...

by al-Tusi and the Maragheh observatory as well as the Arabic Sinjaric Tables by Al-Khazini
Al-Khazini
Abu al-Fath Abd al-Rahman Mansour al-Khāzini or simply Abu al-Fath Khāzini was a Muslim astronomer of Greek ethnicity from Merv, then in the Khorasan province of Persia .-References:...

, an Islamic astronomer of Byzantine Greek descent.

Choniades also visited Tabriz
Tabriz
Tabriz is the fourth largest city and one of the historical capitals of Iran and the capital of East Azerbaijan Province. Situated at an altitude of 1,350 meters at the junction of the Quri River and Aji River, it was the second largest city in Iran until the late 1960s, one of its former...

, at the time the Mongol capital, and served as Orthodox Bishop
Greek Orthodox Church
The Greek Orthodox Church is the body of several churches within the larger communion of Eastern Orthodox Christianity sharing a common cultural tradition whose liturgy is also traditionally conducted in Koine Greek, the original language of the New Testament...

 there. He seems to have been in Tabriz from 1295 to 1296 and returned to Constantinople. In 1302, he returned to Tabriz as Bishop. According to David Pingree, this may have been in connection with Alexios II of Trebizond
Alexios II of Trebizond
Alexios II Megas Komnenos or Alexius II , was Emperor of Trebizond from 1297 to 1330. He was the elder son of John II and Eudokia Palaiologina, and also used the name Palaiologos.- Life :...

's attempt to form an alliance with Ghazan Khan in the summer of 1302.

He died at Constantinople, probably in the second decade of the fourteenth century.

Further reading

  • Pingree, David, "Gregory Choniades and Palaeologan Astronomy," in Dumbarton Oaks Papers, 18, 1964, pp. 135–160.
  • Fryde, Edmund Boleslaw "The Early Palaeologan Renaissance 1261 - C. 1360" 2000

External links

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