Περίληψη : Gregory Chioniades Was One of the Most Important Figures in Mathematics and Sciences in the Late Byzantine Period

IΔΡΥΜA ΜΕΙΖΟΝΟΣ ΕΛΛΗΝΙΣΜΟΥ Συγγραφή : Βενέτης Ευάγγελος Μετάφραση : Βελέντζας Γεώργιος (9/12/2005) Για παραπομπή : Βενέτης Ευάγγελος , "Gregory Chioniades", 2005, Εγκυκλοπαίδεια Μείζονος Ελληνισμού, Κωνσταντινούπολη URL:

Περίληψη : Gregory Chioniades was one of the most important figures in mathematics and sciences in the Late Byzantine period. His decision to travel to Tabriz of Persia in the years of the Il-Khanid dynasty of Mongolia and sit at the feet of the Persian Shams al-Dīn Bukhārī, a famous figure in the field of astronomy at the time, proves his studious bent and wish to keep up with the most modern theories and discoveries in astronomy of the then known world. He learnt the Persian language and could translate various astronomical and medical works to Greek. Άλλα Ονόματα Georgios Τόπος και Χρόνος Γέννησης 1240-1250, Constantinople Τόπος και Χρόνος Θανάτου approximately 1320, Trebizond Κύρια Ιδιότητα astronomer, physician, teacher and bishop

1. The Early Years and his Move to Trebizond

Gregory Chioniades was born in Constantinople between 1240 and 1250.1 His secular name was Georgios. After he was tonsured as a monk in Constantinople, Chioniades moved to Trebizond of Pontos. The city had a long spiritual and intellectual tradition and was an important entrepot along the route connecting the West with Persia at the time. As a result, prosperity and tradition had turned the city into a centre of increased intellectual activity. The Grand Komnenoi of Trebizond supported the notable school of the city. The political, economic and cultural relations between Byzantium and Trebizond remained strong in the late 13th and the early 14th century as well.2 The move of Chioniades to Trebizond and his research activity should be interpreted within this context.

On completing his studies in medical science, Chioniades turned his efforts to the study of astronomy. His interest in astronomy must have been first stimulated in Constantinople, where the science was widespread, and in Trebizond. However, he thought he had better move to Persia, which was the main centre of scientific developments in the field. Chioniades accepted the help offered by Emperor Alexios II Grand Komnenos (1297-1330), who provided him with all the necessary supplies in order to finally travel from Trebizond to Tabriz.3

2. Chioniades in Persia and Scientific Work

In the 1290s Chioniades travelled to Persia and Tabriz, the capital of the Mongolian Il-Khanid dynasty (1256-1335). He lived as a scholar in the royal court and was offered the help of the Mongolian Emperor, possibly Il-Khanid Ghazan (1295-1304).

In Tabriz he stayed for about ten years. He aimed to learn and delve into the scientific developments in astronomy, sponsored and supported by the Mongolian sovereigns.4 The middle-aged Chioniades studied in the royal court under the supervision of the famous Persian astronomer Shams al-Dīn Bukhārī.5 During his stay in Tabriz, Chioniades became a fluent speaker of the Persian language, which helped him grasp scientific developments, write in Persian and then translate Persian works of astronomy into Greek.

Between November 1295 and November 1296 Shams al-Dīn Bukhārī dictated in Persian the ‘Alā’ī Tables (Zīj) of the astronomer

Δημιουργήθηκε στις 1/10/2021 Σελίδα 1/5 IΔΡΥΜA ΜΕΙΖΟΝΟΣ ΕΛΛΗΝΙΣΜΟΥ Συγγραφή : Βενέτης Ευάγγελος Μετάφραση : Βελέντζας Γεώργιος (9/12/2005) Για παραπομπή : Βενέτης Ευάγγελος , "Gregory Chioniades", 2005, Εγκυκλοπαίδεια Μείζονος Ελληνισμού, Κωνσταντινούπολη URL: al-Fahhād to his student Chioniades. Then Chioniades translated the notes from Persian into Greek under the title Persian Astronomical Composition.6 In the spring and autumn of 1296 Chioniades compiled a summary of rules under the title Revised Canons, aiming to improve the accuracy of some astronomical laws. The attempt is typical of his familiarity with the abbreviated Arabic text Sanjarī Tables (Zīj) by al-Khāzinī, as well as the Persian Īlkhānī Tables by Nasr al-Dīn Tusī. In the same period Chioniades translated several other works, such as Astrolabe by Shams al-Dīn Bukhārī and the Introduction by Tusī (this very translation in Greek travelled to the west).7 After 1302 Chioniades translated a short dissertation on antidotes from Persian to Greek (Ambros. Q 94 sup., f. 336-347).

In September 1301 Chioniades returned to Trebizond bringing back a rich library from Persia, while the following year (April 1302) he went to his birthplace, Constantinople. In Trebizond he taught astronomy and medicine. In this way, he created a wide circle of students in these scientific fields.

The long stay of Chioniades in Persia, his association with the Persian thought and principles as well as his particular interest in astrology possibly influenced his comprehensive conception of the world. As a result, the Byzantines accused him of heretic declensions. In order to defend himself, Chioniades drew up a confession of faith under the title Confession of Iatrosophist Chioniades.8 Furthermore, during his stay in Trebizond, Chioniades wrote some notes on Dialectics and On the Orthodox Faith of St. John of Damascus.9

Among the clerical and bureaucratic duties he assumed in Persia from the early 14th century on, Chioniades wrote and sent a series of letters to the Patriarch of Constantinople, the ninth of them being preserved. Then he returned to Trebizond, where he retired as a monk. In the last years of his life Chioniades suffered from ageing and loneliness.10 After his death, circa 1320, part of his library was bequeathed to Constantine Loukites.

3. The Political and Diplomatic Role of Chioniades

Apart from his irrefutably great contribution to sciences, Chioniades played an important role in politics as well. In particular, the originally Shamanistic dynasty of the Il-Khanid Mongols followed a hostile policy towards Islam from 1251 until the late 13th century. The founder of the dynasty Hülegü (1251-1265) favoured Christianity in Persia thanks to the religious toleration of the Il-Khanids. In the early 14th century the Catholic Church tried to take advantage of the favourable policy of the Il-Khanids towards Christianity. The Patriarchate of Constantinople and the imperial court acted similarly. The excellent relations between Chioniades and the Grand Komnenoi of the Empire of Trebizond guaranteed the harmonious settlement of the matter in Constantinople and Trebizond. Moreover, Chioniades was the proper person to become a bishop in the capital of the Il-Khanids thanks to his awareness of Persian matters and his long stay in the country, his fluent Persian language as well as his close acquaintance with the Persian culture. The Il- Khanid sultan Ölgeitü (1304-1316) gave his permit and Byzantium sent Chioniades to Persia in order to become the bishop of Tabriz under the name Gregory. He held this post for more than five years and was responsible for the interests of the Christian population not only in Tabriz but in the entire Il-Khanid territory as well. The appointment of Chioniades as a bishop was the first movement of the Patriarchate of Constantinople against the rival Western Church in Persia.

4. General Evaluation

Chioniades was a multilateral personality. He pioneered in astronomy in Byzantium. His decision to move to Persia contributed to the promotion of astronomical studies and to the closer cultural relations between the Greek and the Persian world. The texts of Chioniades influenced a lot of scholars that came later on, such as George Chrysokokkes and Theodore Meliteniotes. Together with his research activities, Chioniades acted on a political level as well due to his priesthood. The Christian community of Persia thought of him as a figure of particular importance thanks to the influence he had over the Patriarchate of Constantinople; as a result, he contributed greatly to the improvement of political relations between the Byzantine world and the Il-Khanid dynasty of Persia.

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1. The letters of Gregory Chioniades constitute an important source of information regarding his life, and more specifically the sixteen letters that are now kept in Rome and are called ως Του σοφωτάτου και λογιωτάτου Γρηγορίου του Χιονιάδου επιστολαί. See Παπαδόπουλος, Δ., «Γρηγορίου Χιονιάδου του αστρονόμου επιστολαί», Επιστημονική Επετηρίς Φιλοσοφικής Σχολής Πανεπιστημίου Θεσσαλονίκης 1 (1927), pp. 151‑205.

2. Vogel, K., “Byzantine Science”, στο The Cambridge Medieval History II (Cambridge 1966), pp. 277-8.

3. Pingree, D., “Gregory Chioniades and Palaeologean Astronomy”, Dumbarton Oaks Papers 18 (1964), p. 141.

4. Oxford Dictionary of Byzantium 1 (Oxford 1991), p. 423, see entry “Chioniades” (D. Pingree).

5. Shams al-Dīn Bukhārī was born on June 11th 1254 in Bukhārā of Central Asia and was the writer of the Persian version of the story Zīj ‘Alā’ī.

6. Pingree, D., “Fahhad, Farid al-Din Abu’l-Hasan ‘Ali b. ‘Abd al-Karim Sharvani”, Encyclopaedia Iranica 9 (1999), pp. 157-8.

7. Swerdlow, N. – Neugebauer, O., Mathematical Astronomy in Copernicus De revolutionibus 1 (New York 1974), p. 47.

8. Westerink, L.G., “La profession de foi de Grégoire Chioniadès”, Revue des Etudes Byzantines 38 (1980), pp. 242-5.

9. Westerink, L.G., “La profession de foi de Grégoire Chioniadès”, Revue des Etudes Byzantines 38 (1980), p. 237.

10. Παπαδόπουλος, Δ., «Γρηγορίου Χιονιάδου του αστρονόμου επιστολαί», Επιστημονική Επετηρίς Φιλοσοφικής Σχολής Πανεπιστημίου Θεσσαλονίκης 1 (1927), p. 173.

Βιβλιογραφία : Hunger H., Βυζαντινή Λογοτεχνία. H λόγια κοσμική γραμματεία των Βυζαντινών, 3, MIEΤ, Αθήνα 1994

Leichter J.G., The Zīj as-Sanjarī of Gregory Chioniades (αδ. διδ. διατριβή) Text, Translation, and Greek- to-Arabic Glossary, Brown University 2004

Morgan D., Medieval Persia 1040-1797, London 1988

Pingree D., "Chioniades", Kazhdan A., ODB 1, Oxford – New York 1991, 423-424

Paschos Ε.A., Sotiroudis P., The schemata of the stars; Byzantine astronomy from A.D. 1300, Singapore 1998

Swerdlow N., Neugebauer O., Mathematical Astronomy in Copernicus De revolutionibus 1, New York 1974

Pingree D., "Gregory Chioniades and Paleologan Astronomy", Dumbarton Oaks Papers, 18, 1964, 133-160

Pingree D., "In Defense of Gregory Chioniades", Archives Internationales d’Histoire de Sciences, 35, 1985, 436-438

Pingree D., "Fahhad, Farid al-Din Abu'l-Hasan 'Ali b. 'Abd al-Karim Sharvani", Encyclopaedia Iranica 9, 1999, 157-158

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Vögel K., "Byzantine Science", Hussey, J.M. (ed.), The Cambridge Medieval History, 4.2, Cambridge 1966, 265-305

Westerink L.G., "La profession de foi de Grégoire Chioniadès", Revue des Etudes Byzantines, 38, 1980, 233-245

Παπαδόπουλος Δ., "Γρηγορίου Χιονιάδου του αστρονόμου επιστολαί", Επιστημονική Επετηρίς Φιλοσοφικής Σχολής Πανεπιστημίου Θεσσαλονίκης, 1, 1927, 151-205

Pingree D., The Astronomical Works of Gregory Choniades, 1, Amsterdam 1985

Pingree D., The Astronomical Works of Gregory Choniades, 2, Amsterdam 1986

Δικτυογραφία : Rome Reborn http://www.loc.gov/exhibits/vatican/math.html The History of Byzantine Literature: from Justinian to the end of the Eastern Roman Empire http://www.byzantine.nd.edu/krumbacher.htm Хиониад Григорий (Chioniades) http://encyclopedia.astrologer.ru/cgi-bin/index?H/Chioniades.html

Πηγές Pingree, D. (ed.), The Astronomical Works of Gregory Choniades, 2 vols. (Amsterdam 1985‑1986).

Παπαδόπουλος, Δ., «Γρηγορίου Χιονιάδου του αστρονόμου επιστολαί», Επιστημονική Επετηρίς Φιλοσοφικής Σχολής Πανεπιστημίου Θεσσαλονίκης 1 (1927), pp. 151‑205.

Παραθέματα From Chioniades letter to emperor Alexios Komnenos

Τοῦ αὐτοῦ πρὸς τὸν Τρισμακάριστον καὶ τρισαλκιμώτατον ἐκεῖνον Κύριον Ἀλέξιον βασιλέα τὸν Μέγαν Κομνηνόν. (Φ. 26α – 27α)

«Ἡλιοειδέστατε βασιλεῦ, ἡ τὰ πάντα διεξάγουσα καὶ διακρατοῦσα εἰδοποιὸς καὶ παντοκρατικὴ δεξιὰ τοῦ μεγάλου θεοῦ καὶ σωτῆρος ἡμῶν Ἰησοῦ Χριστοῦ εἴη διὰ φρουροῦ...».

(Παπαδόπουλος, Δ., «Γρηγορίου Χιονιάδου τοῦ ἀστρονόμου ἐπιστολαί», Επιστημονική Επετηρίς Φιλοσοφικής Σχολής Πανεπιστημίου Θεσσαλονίκης 1 (1927), σελ. 151‑205).

Χρονολόγιο 1240-1250: Birth of Chioniades in Constantinople beginning of 1920s: Chioniades travels to Persia and Tabriz

November 1295-November 1296: The ‘Alā’ī Tables of the astronomer al‑Fahhād are written in Persian

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September 1301: Chioniades retunrns to Trebizond

1302: Chioniades returns to Constantinople and founds his ʺschoolʺ

1305: Chioniades becomes the bishop of Tabriz under the name Gregory

1320: Death of Chioniadee in Trebizond

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