| From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 229 |
|
Courtesy of 
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Chioniades, Gregor
[George]
Katherine Haramundanis
Born Constantinople
(Istanbul, Turkey), circa 1240
Died Trebizond (Trabzon,
Turkey), circa 1320
Born
in Constantinople and christened George, Chioniades became a physician. Greatly
attracted to mathematics, astronomy, and medical astrology, he chose to travel
to Persia to further his studies. Early in 1295, he went to Trebizond (Trapezus)
where he found favor with the emperor of Trebizond John II Komnenos (reigned:
1280–1297), who supported his travel and study in Persia. Between November
1295 and November 1296 he was received at the court of the Mongol Īlkhāns
at Tabrīz where he studied astronomy and astrology with Shams
al‐Dīn al‐Bukhārī, an astronomer and teacher
from Bukhārā in Central Asia. Shams al‐Dīn was the author
of a Persian treatise on the astrolabe that Chioniades later translated into
Greek.
During
his stay in Tabrīz, Chioniades amassed an important collection of astronomical
works in Persian and Arabic that he took with him on his return to Trebizond
and later to Constantinople. Some of these works he translated into Greek,
adding commentaries and incorporating his own notes written in Greek, Persian,
and Arabic from his studies with Shams al‐Dīn. Chioniades founded
schools for the study of astronomy and medical astrology in both Trebizond
and Constantinople.
By
September 1301 Chioniades had returned to Trebizond, and by April 1302 he
was in Constantinople. He translated into Greek a set of recipes for antidotes
and wrote a confession of faith to refute suspicions of heresy based on his
work in astrology and his sojourn with the Persians. In 1305, appointed Bishop
of Tabrīz, Chioniades took the name Gregory. He remained in Tabrīz
until about 1310, retiring for his final years as a monk to Trebizond. Chioniades
left part of his library to Constantine Loukites. His translations from Persian
into Greek assisted in the transmission of this material to the medieval and
Renaissance worlds of the west.
Chioniades'
work associated with astronomy includes his translations of several astronomical
works from Persian or Arabic into Greek, including the Zīj al‐ʿAlāʾī (The Alai astronomical
handbook with tables), the Persian Astronomical Composition, and the
Revised Canons. Translations of two astronomical tables, Khāzinī's
Sanjarī Zīj and Ṭūsī's Īlkhānī
Zīj, are also considered to be by Chioniades. He translated the work
on the astrolabe written by Shams al‐Dīn and wrote a short introduction
to astronomy, The Schemata of the Stars. His translations and body
of work provide evidence that Byzantine astronomers preserved scientific ideas
from Ptolemy
and Islamic scientists and further added their own contributions, making observations
and refining existing cosmological models. Chioniades' introduction to astronomy
includes diagrams of the models based on the Ṭūsī
couple, which refined current cosmological theory and which was used by Nicholas
Copernicus in his work on the heliocentric Solar System.
Selected References
Paschos,
E. A. and P. Sotiroudis (1998). The Schemata of the Stars: Byzantine Astronomy
from A.D. 1300. Singapore: World Scientific.
Pingree, David (1964). “Gregory Chioniades and Palaeologan Astronomy.”
Dumbarton Oaks Papers 18: 133–160.
——— (1985). The
Astronomical Works of Gregory Chioniades. Vol. I, The Zīj al‐ʿAlāʾī. Amsterdam:
J. C. Grieben.
——— (2002). “Chioniades,
Gregory.” In Oxford Dictionary of Byzantium, edited by Alexander P.
Kazhdan, pp. 422–423. New York: Oxford University Press.
Westerink,
L. G. (1980). “La profession de foi de Gregoire Chioniades.” Revue
des études byzantines 38:
233–245.