1. History of the Text – Publication

The Αstronomical Tribiblos by Theodore Meliteniotes is considered one of the most comprehensive and important texts on astronomy in the Byzantine period. The work was called Tribiblos as it included three books. So far, only the first two have been published, in an annotated edition by Régine Leurquin in the series Corpus des Astronomes Byzantins.¹

The work was written in the second half of the 14th century, while the title must have been given after 1368. So implies the title of the first book’s introduction, which reads: «by the megas sakellarios and didaskalos ton didaskalon of the great holy Church of God and archdeacon, Theodore Meliteniotes, the first introduction to Astronomical Tribiblos». Theodore Meliteniotes took the office of archdeacon in 1368 and retained it for 25 years, until he died.² Therefore, there is a terminus ante quem concerning the completion of the Τribiblos. The work was probably written between 1360 and 1368.

The Astronomical Tribiblos must not have been particularly popular, judging from the number of manuscripts (about ten) of the first two books preserved so far in the collections of the greatest European libraries (Rome, Paris, London, Madrid, etc.). The original (Vaticanus gr. 792, ff. 24v-353v et 361) is in the Vatican Apostolic Library, where three more copies of the 14th and the 15th century may be found, while only two out of the ten manuscripts have preserved the work in total.

The third book is special. It seems that at some point this book, which included elements of Persian astronomy, was detached from the other two books and started to circulate separately under the title Paradosis eis tous persikous proxeirous kanonas («Tradition to the Persian Rough Tables»). The book, preserved in more than thirty manuscripts, came out at times as a work of either Isaac Argyros, to whom was attributed until recently, or of George Chrysokokkes.³

2. Content

The Αstronomical Tribiblos is one of the most massive works on astronomy. It included all the important issues defining the discussion about astronomy in the Paleologean era, when sciences became one of the fields that attracted the scholars' particular interest. Such discussions led to the formation of respective trends in astronomy. One of them was followed by the scholars who introduced and adopted elements of the Persian and Arabic astronomy, along with the Ptolemaic tradition introduced by Gregory Chioniades and followed by George Chrysokokkes. This trend influenced the astronomical works of Theodore Meliteniotes, who, though following Ptolemy, knew and introduced elements of the Persian astronomy for the sake of comparison.⁴

The work of Meliteniotes is written in topical units. In the introduction the writer says that he is absolutely against astrology, in accordance with the tradition formed mainly because of the unfriendly attitude of the Church towards it. Meliteniotes makes his point against astrology in the first place in order to defend his involvement in the science of astronomy.⁵ Then, in the first book, the writer presents those elements of arithmetic considered necessary for astronomy students, while in the second book he presents the basic elements of the Ptolemaic system. The third book is focused on Persian astronomy.

The work aimed to introduce the science of astronomy to the readers and offer them all they needed to continue studying this science. Thus, it starts from basic principles, which the writer considers necessary for further reading. For example, the first chapter of the first book is a kind of introduction to astronomy, as it answers to questions such as what astronomy is, what its origins are and how it was handed down to the ‘Greeks’, what the Syntaxis Mathematica by Claudius Ptolemy is and what the content of its thirteen books is. It proceeds with calculation issues, such as ‘On Multiplications’ and ‘On Partitions’, thus offering to the readers all they needed to keep up with the following chapters and proceed to calculations on their own. A great part of the first book includes the issue of the manufacture and use of the astrolabe.

The third book, the Paradosis eis tous persikous proxeirous kanonas ["Tradition to the Persian Rough Tables"], follows the book on astronomy written by George Chrysokokkes, the Introduction to the Syntaxis of the Persians. Meliteniotes in this part of the work follows Chrysokokkes and makes the same mistakes, although he attempts to improve the Ptolemaic tables in order to make them seem more accurate.⁶ But already since Nikephoros Gregoras had written his own work, before 1330, it was widely accepted that the Ptolemaic tables needed corrections.

In terms of methodology, the work follows the tradition of the Byzantine texts on astronomy, starting from elementary and rudimentary knowledge and proceeding to special topics. The particular work is characterised by detailed description.

Meliteniotes aims to compare the very long Ptolemaic tradition with the more recent Persian one. He used the same examples in both books so that the differences could be more easily understood.

3. Evaluation