Severus Sebokht of Nisibis flourished in the early-mid 7th century and was bishop of the great convent of Kenneshrin (the "Eagle's nest") at which Greek was studied extensively. He was one of the foremost scientific writers of his time. His works are mainly scientific or philosophical in character, although little has been translated into English.
He is best known today for a remark which shows that what we call today "Arabic" numerals were coming into use.
- 1 Works
- 2 Extracts from the handbooks
- 3 Material from Hugoye-List
- 4 Material from the internet
- 5 Manuscripts
- 6 Bibliography
- 7 References
- 8 Links
- On the astrolabe.
- On the constellations, against the astrologers.
- Letters to Basil, a priest of Cyprus.
Extracts from the handbooks
Material from Nau, Le traite..., ROC 1929
Severus Sebokht is mainly known as a populariser of Greek philosophy among the Syrians . But thanks to a manuscript brought to France by Addai Scher, we now know that he also played an important role in the transmission of Greek science. The manuscript, now Paris, Syriaque 346, dated 1309 AD, contains his correspondence, in the last years of his life, only with an otherwise unknown Basil, a priest in Cyprus, so if we may conclude that he wrote 27 chapters over a number of years to a single correspondant, his scientific activity must have been considerable.
The first 18 chapters (folios 78-121v) form a distinct treatise with an incipit and explicit. Severus refers to it in a later writing in the same manuscript.
The first 5 chapters are directed against astrologers. These attributed to the constellations effects on earth which were in line with their names. Severus shows at length that these names are arbitrary, purely conventional, and so have no connection with the real nature of the stars. Chapter 4 contains long quotations from Aratus which are mostly missing in our Greek texts of the Phenomena of this author. Chapter 5 contains an interesting selection of Syriac technical astrological jargon, used previously by Bardesanes in his Book of the laws of the countries and also the Syriac names of the constellations and principal stars, in use throughout the treatise. The Syriac text of these chapters was published by Nau because of its use to Syriac scholars.
Severus then goes on to give a cosmography, which must have been very much in fashion at the time, since it was the basis of astrology. He lists the number of constellation, their names, remarkable stars, when these rise and set, the signs of the zodiac, the milky way, etc.
Two short extracts of chapters 17 and 18 have already been published by Sachau (Inedita Syriaca, Vienna (1870), pp.127-134) from BL. Add. 14538, a ms. of the 10th century.
The fragments of the works of Severus may be found in manuscripts in Paris, the BL, Cambridge, Berlin, and Notre-Dame des Semences. The author is always called 'of Nisibis' or 'Nisibite'; also Abbot, and bishop of Qenneshrin. He therefore came from Nisibis. Despite his Persian name "Sebokht" he proclaims himself a Syrian. However he must have known Persian, since a translation is attributed to him of a commentary on the peri hermenias, composed by Paul the Persian, from Persian into Syriac. (Cf. Journal Asiatique, juillet-aout 1900, p.73).
He must have been the abbot of the monastery of Qenneshrin, and then "bishop of Qenneshrin". As M. A. Baumstark has well said , he was never "bishop of Nisibis".
It is not impossible that the fragments on Gregory Nazianzen in Ms. British Library Add. 14517 (14547?), fol. 236-240, catalogued by Wright on p.432, are also by Severus Sebokht since they are there attributed to a "Severus, bishop, Nisibite" rather than "bishop of Nisibis", which is precisely the status of Severus Sebokht.
In June 638, he wrote on the works of Aristotle.
According to the Maronite Chronicle, in 659 he assisted the monophysite patriarch, Theodore, in a debate with the Maronites before Moawiah (cf. ROC vol. 4, (1899), p.323); the monophysites got the worst of the debate, and Moawiah ordered that they should live quietly, and pay him 20,000 dinars a year in return for his "protection".
By 661 he had written his treatise on the Astrolabe, since he refers to it in two places in his work on the Constellations, written in 661.
In 662, he wrote a letter on the era of the birth of Christ; a chapter on the various climates or zones (ms. 346, fol. 134) is also from this period, because it refers to the work on the Constellations.
Finally there is a treatise on the date on which Easter should be celebrated in 665 AD, which is probably by him. Severus probably died in that year, although Baumstark  places his death in 666-7.
In his work are found passages from Theon, Aratus, but above all from Ptolemy. He seems to have known most of Ptolemy's works: the Geography, the Mathematical Composition (=Almagest), the Manual tables, and the works of astrology; the Quadripartium and its epitome, the "book of fruit".
Material from Wright
Severus Sebokht (d. 666-7 A.D.) 1 of Nisibis 2, bishop of the convent of Ken-neshre, at this time one of the chief seats of Greek learning in western Syria 3 flourished at the same time as Marutha, under the patriarch Athanasius Gammala (died in 631 4) and his successor John.
He devoted himself to philosophical and mathematical as well as theological studies 5. Of the first we have specimens in his treatise on the syllogisms in the Analytica Priora of Aristotle, his commentary on the Περι ερμηνείας, and his letters to the priest Aitilaha of Mosul on certain terms in the Περι ερμηνείας, and to the periodeutes Yaunan or Jonas on some points in the logic of Aristotle 6. Of his astronomical and geographical studies there are a few examples in Brit. Mus. Add. 14538, ff. 153-155 7, such as whether the heaven surrounds the earth in the form of a wheel or sphere, on the habitable and uninhabitable portions of the earth, on the measurement of the heaven and the earth and the space between them, and on the motions of the sun and moon 8. In the Royal Library at Berlin there is a short treatise of his on the astrolabe 9.
More or less theological in their nature are his letter to the priest and periodeutes Basil of Cyprus, on the 14th of Nisan, A. Gr. 976 (665 A.D.) 10, a treatise on the weeks of Daniel 11, and letters to Sergius, abbot of Shiggar (Sinjar), on two discourses of Gregory Nazianzen 12. He is also said to have drawn up a liturgy 13.
- On the Persian name Sebokht see Noldeke, Gesch. des Artachsir i Papakan, in Beitrage z. Kunde d. indogerm. Sprachen, iv. 49, note 4; Geschichte d. Perser und Araber, p. 396, note 1.
- See Wright, Catal., p. 598, col. 1.
- See B.O., ii. 335 ; Bar-Hebraeus, Chron. Eccles., i. 275.
- According to Bar-Hebraeus, Chron. Eccles., i. 275 ; B.O., ii. 334. Dionysius of Tell-Mahre gives 644.
- Compare Renan, De Philos. Peripat. ap. Syros, pp. 29, 30.
- See Brit. Mus. Add. 14660 and 17156 (Wright, Catal., pp. 1160-63), and the Catal. of the Royal Library of Berlin, Sachau 226, 6, 9.
- Wright, Catal., p. 1008.
- See Sachau, Ined. Syr., pp. 127-134.
- Alter Bestand 37, 2 (Kurzes Verzeichniss, p. 32).
- Same MS., 3.
- Wright, Catal., p. 988, col. 2.
- Ibid., p. 432, col. 2.
- B.O., ii. 463.
Material from Sebastian Brock
Severus Sebokht (W; d.666-7). Bishop of the monastery of Qenneshre, and one of the most learned men of his time in the fields of astronomy and philosophy. Several works of his in both these fields survive, notably treatises on the Astrolabe and on the Constellations, letters on points of logic addressed to Aitalaha of Nineveh and to a periodeutes Yaunan, and a treatise on Syllogisms (written in 638). He also translated from Middle Persian a compendium on logic written by Paul the Persian for the Persian shah Khosro I (d. 579).
Material from Hugoye-List
Steven Ring wrote
There are some MSS I know of:
1. There is a MS of his treatise on Aristotle's Analytica Priora in Mingana MS Syr 44 part G which is preceded by the same work of Aristotle in Syriac translation. See Mingana's catalogue, volume 1 column 114. This West Syrian MS is dated AD 1575 and it was written in Deir Zafaran, (The Saffron Monastery).
Other links: He was the tutor of the distinguished scholar Jacob bishop of Edessa, see my entry under AD 684: http://www.ashu39.dsl.pipex.com/ChristianMysteries/chron_tab7.html
More info from online
The Journale Asiatique is mostly online at http://gallica.bnf.fr.
- There is a very useful overview of Severus Sabukht’s work and references to the relevant manuscripts in Ignatius Aphram I Barsoum’s The Scattered Pearls: A History of Syriac Literature and Sciences, 2nd rev. ed (Gorgias Press, 2003), 325-28.
- Gerrit Reinink has an article on Severus's work on Aristotelian logic ("Severus Sebokts Brief an den periodeutes Jonan. Einige Fragen zur aristotelischen Logik") in III Symposium Syriacum 1980: Les contacts du monde syriaque avec les autres cultures, ed. Rene Lavenant (Rome: PISO, 1983), 97-107.
- According to google book search's scan of page 48 of A History of Mathematical Notations, by Florian Cajori (1993):
- "The earliest-known reference to Hindu numerals outside of India is the one due to Bishop Severus Sebokht of Nisibus, who, living in the convent of Kenneshre on the Euphrates, refers to them in a fragment of a manuscript (MS Syriac [Paris], No. 346) of the year 662 A.D."
- Nau's ROC article (Revue de l'Orient chrétien 15) discusses the texts in Paris ms 346.
and from John M. McMahon:
- For SS's astronomical works, the two most important mss. date from 1309 (Paris MS Syr. 346) and from 1556 (Berlin MS Syr. 186). Several of the works in these are available in modern translations:
- For SS's Treatise on the Astrolabe see F. N. Nau, "Le Traité sur l'Astrolabe Plan de Sévère Sébokt," Journal Asiatique 13 (1899): 56-101, 238-303. An English version (from Nau's French) is in R. Gunther, The Astrolabes of the World Vol. 1: The Eastern Astrolabes (Oxford: 1932): 82-103.
- SS's work on the constellations is in F. N. Nau, "Le Traité sur les 'Constellations' Écrit, en 661 (sic), par Sévère Sébokt, Évêque de Qennesrin" Revue de l'Orient Chrétien 7 (27) (1929): 327-410; 8 (28) (1932): 85-100.
- For SS's explanation of lunar eclipses see F. N. Nau, "Notes d'Astronomie Syrienne," Journal Asiatique 16 (1910): 209-28, esp. 219-224.
- Life and works of SS:
- F. N. Nau's "La Cosmographie au VIIe Siècle chez les Syriens," Revue de l'Orient Chrétien 5 (18) (1910): 225-54 assesses Severus's contributions and surveys the contents of Paris MS Syr. 346, three quarters of which is made up of his works.
- W. Wright, A Short History of Syriac Literature (Amsterdam: 1966): 137-9.
- I. Afram Barsoum, History of Syriac Literature and Sciences. Translated by Matti Moosa (Pueblo, CO: 2000, originally published as Kitab al-Lulu al-Manthur fi Tarikh al-Ulum wa al-Adab al-Surynaniyya [Hims, Syria: 1943]): 65, 108, which conveniently lists and briefly discusses all of Severus's works.
--- Ute Possekel wrote:
Nau, in the article I mentioned, is interested in astronomical data, and he quotes from that ms. a letter by Severus to a Cypriote priest named Basil from AD 662, in which he refers to Bardaisan’s computations of planetary conjunctions, the section on Arabic numbers. The same ms. apparently also had Severus’ treatise on the latitude of climata, and perhaps the one on the astrolabe. The latter is ed. Nau, Journal Asiatique, 9th series, vol. 13, 1899. I am not sure what the ms. is for this one, though.
--- joel walker wrote:
For an overview of the broader cultural context for the transmission of Aristotelian logic and Greek medicine into Syriac during the sixth century, you might want to read the third chapter of my new book, The Legend of Mar Qardagh: Narrative and Christian Heroism in Late Antique Iraq (UC Press, 2006). Sergius of Resh Aina holds a key place in my argument.
If you haven't done so already, you should also check the entries under Severus Sebokht and philosophy in Syriac Studies. A Classified Bibliography (1960-1990) (Kashlik, Lebanon, 1996). I thhink there are some later supplements published in Parole de l'Orient, and after that, in Hugoye.
Material from the internet
He wrote letters on theological subjects to Basil of Cyprus and Sergius, abbot of Skiggar, as well as two discourses on St. Gregory Nazianzen. On Aristotelian logic he composed a treatise on the syllogisms in the Analytics of Aristotle, a commentary on the Hermeneutics which was based on the commentary of Paul the Persian, a letter to Aitilaha of Mosul on certain terms used in the Hermeneutics (Brit. Mus. Add. 17156), and a letter to the periodeutes Yaunan on the logic of Aristotle (Camb. Univ. Lib. Add. 2812).
In addition to these works on logic he also wrote on astronomical subjects (Brit. Mus. Add. 14538), and composed a treatise on the astronomical instrument known as the astrolabe, which has been edited and published by F. Nau (Paris, 1899). In all this he showed himself the product of Alexandrian science and illustrated the widening scientific interests of the period. It seems that he took steps towards introducing the Indian numerals, but this was not carried on by any immediate successor. His work represents the highest level reached by any Syriac scientist and this, it will be noted, was associated with Kennesrin.
In 662AD he wrote concerning the new numerals, which were moving West and were to become what we know as 'Arabic' numerals:
- I will omit all discussion of the science of the Indians, ... , of their subtle discoveries in astronomy, discoveries that are more ingenious than those of the Greeks and the Babylonians, and of their valuable methods of calculation which surpass description. I wish only to say that this computation is done by means of nine signs. If those who believe, because they speak Greek, that they have arrived at the limits of science, would read the Indian texts, they would be convinced, even if a little late in the day, that there are others who know something of value. (Found online: supposed to come from "The Wonder That Was India, A Survey of the Culture of the Indian Sub-Continent Before the Coming of the Muslims", by A.L. Basham, Reader in the History of India in the University of London, Sidgwick and Jackson, London, 1954, repr. 1961).
According to google book search's scan of page 48 of A History of Mathematical Notations, by Florian Cajori (1993):
- The earliest-known reference to Hindu numerals outside of India is the one due to Bishop Severus Sebokht of Nisibus, who, living in the convent of Kenneshre on the Euphrates, refers to them in a fragment of a manuscript (MS Syriac [Paris], No. 346) of the year 662 A.D.
- Like many of his contemporaries, Severus was bicultural, partaking of the Byzantine Greek influence on Western Syrian intellectual circles while fully immersed in his own Syrian cultural milieu. He does, however, criticize the contemporary Greek tendency to assume intellectual superiority and asserts his own capabilities as a native Syrian, raising a strong polemical voice against the cultural hegemony of the Greek-speaking world over that of provincials. A leading figure in the teaching and commentary tradition of Aristotelian philosophy, especially in logic and syllogisms, Severus produced a Discourse on Syllogisms in Prior Analytics (638 CE) and wrote commentaries on other philosophical texts. He translated into Syriac Paul the Persian's commentary on Aristotle's De interpretatione ... He was familiar with Ptolemy's Handy Tables, and there is some indication that he translated the Almagest into Syriac; in any case, he most certainly taught it in the school of Nisbis and then later in Western Syria ...
- Specialized treatments of Severus and his contemporaries appear in S. Brock, "From Antagonism to Assimilation: Syriac Attitudes to Greek Learning" in Syriac Perspectives on Late Antiquity (London: 1984): V, 17-34, esp. 23-4, 28 and in two works by D. Pingree: "The Greek Influence on Early Islamic Mathematical Astronomy," Journal of the American Oriental Society 93 1993: 32-43, esp. 34-5; and "The Teaching of the Almagest in Late Antiquity" in The Sciences in Greco-Roman Society. ed. T. Barnes. (Edmonton: 1994): 73-98, esp. 94-5.
From google book search, in "Aristotelian Meteorology in Syriac: Barhebraeus, Butyrum Sapientiae, Books of Mineralogy ..." By Hidemi Takahashi, p. 325, it states that Severus was familiar with Ptolemy's Handy Tables (see the French translation of "On the Constellations" by Nau , p.240; Nau [1930-1], p.343 (index)), as was Sergius of Reshaina (Sachau  225.17).
The following manuscripts contain works by Severus Sebokht.
Ms. Paris Syriaque 346
This manuscript contains a large quantity of works by Severus Sebokht, and is the main source for his works. 
The Syriac manuscripts 1-288 are described by Herman Zotenberg in his Catalogue des manuscrits syriaques et sabéens (mandaïtes) de la bibliothèque nationale, Paris (1874), which was completed for mss. 289-334 by J-B. Chabot. The following manuscripts are described in a handwritten supplement to Chabot's catalogue, which can only be consulted in the "Salle Orientale" (Oriental reading room) at the Bibliotheque Nationale.
Ms. Syr. 346 has a relatively detailed description at the head of the volume, probably by Chabot, on the first guard-leaf. It contains 177 f. The first 36 folios are missing. It is written in a fine Serto hand. Each page has 28 lines, and is 160 x 120 mm.
It contains a collection of various treatises on astronomy, most of them by Severus Sebokht of Nisibis. Here is a list of contents. (The attributions are elderly and perhaps need revisiting).
- ff. 1-36 : Ptolemy. Megale suntaxis in Syriac. Unpublished.
- f. 36v-51v : Severus Sebokht of Nisibis. Treatise on the figures of the astrolabe. This text was edited by the abbé François Nau, Paris 1899 (available at the BNF Richelieu, manuscrits orientaux, imprimé 8° imp or 116 (9.13)).
- ff. 51v-77v. Severus Sebokht of Nisibis. Treatise on the causes of solar and lunar eclipses, winds and other natural phenomena.
- f. 78r-121v. Severus Sebokht of Nisibis. The figures of the zodiac. According to the author of the catalogue notice, only the last chapter is known and may be found in a Syriac ms in the British Library, Mss Add. 14538, published by Eduard Sachau in Inedita Syriaca, Wien (1870), pp. 127-134.
- ff. 122-145. Severus Sebokht of Nisibis. The reunion of the seven planets, how to predict an eclipse of the sun, the seven climates of the earth and how to measure them, the division of heaven into 5 zodiacs, and two chapters : one is devoted to the 14th month ("consacree au 14e lune"), the other to the cycle of 95 years and the birth of Christ. They were copied at the request of Basil of Cyprus.
- ff. 145r-161r. Giwargi (Georges, bishop of the Arab tribes) : the birth of the year, the movement of the stars, and the influence of the moon and a corresponance with John the Stylite, published by Viktor Ryssel (Georgs, des Araberbischofs, Gedichte und Briefe... Leipzig, 1891).
- ff. 161v-168v. Barhebraeus. Hymns on the heavenly bodies.
- ff. 168v-171. Severus Sebokht of Nisibis. History of astronomy among the Assyrians.
- f. 171v. Treatise on Astronomy.
- ff. 172-177v : Severus Sebokht of Nisibis. Treatise on Astronomy.
- Colophon on f. 168v : Finished in 1309 at the monastery of Mar Hanania, Mardin.
The very brief notice in the catalogue mentions the existence of 13 ff. detached from this manuscript and forming ms. Syriac 392. Laurent Héricher adds that apparently only the first 8 folios can be from ms. Syriaque 346. The folios are very damaged and practically illegible. They have been folded in half.
The manuscript was brought to France by Addai Scher. 
British Library Ms. Additional 14538
This manuscript contains "Treatises against heresies, and other theological works; very imperfect. On vellum, of the XIth or XIIth century. Quarto." 
The works of Severus Sabocht occupy folios 153b- 155a.
- 1.On the length of the day and night;
- 2.whether the heaven surrounds the earth;
- 3.habitable and uninhabitable portions of the earth;
- 4.on the measurement of the heaven and earth;
- 5.motion of the sun and moon.
These are the texts attributed to Severus, which were edited and published by Sachau in Inedita Syriaca.
More information is apparently available in W. Wright, Catalogue of Syriac manuscripts in the British Museum, London (1871). A full description of Add.14,538 is available in vol.II, pp.1003-1008.  But this I have not seen.
In Wright's catalogue, on p.1008, we find the following details. The manuscript contains various works. The 5th part of it is as follows:
5. Several sections relating to astronomical and geographical subjects. Each seems to be on a single page -- RP. a) On the length of the day and night in different parts of the earth. Imperfect. fol. 153a. (No author given by Wright). b) Severus Sabocht, bishop of Kinnesrin. Whether the heaven surrounds the earth in the form of a wheel or a sphere. Imperfect. Fol. 153b. c) Severus Sabocht. Extract regarding the inhabitable and uninhabitable portions of the earth, etc. Fol. 154a. See Sachau, Inedita Syriaca. d) Severus Sabocht. On the measurement of the heaven and the earth, and the space between them. Imperfect. Fol. 154b. See Sachau, Inedita Syriaca. e) The conclusion of an extract and the motions of the sun and the moon. Fol. 155a. See Sachau, Inedita Syriaca. (No author given by Wright). f) Basil: on the motion of the sun between the tropics. Fol. 155a. g) Jacob of Edessa, how the heathen came to think that the sun, moon and stars were living and rational beings endowed with free-will.
Berlin Ms. Petermann I 26 (once Ms. 186 in the Sachau catalogue)
Manuscript Petermann I 26 (Catalogue Sachau 186) contains various works by Severus Sebokht. The treatise on the astrolabe is contained on folios 82b-98a. For details you should refer to the catalogue by Sachau, volume 2, published in 1899. 
Alqosh, Monastery of Rabban Hormizd (Notre-Dame des Semences), Ms. 50
The catalogue with brief descriptions of this library as it was in 1906 is available online,  and gives the following details.
Codex 50 has the title "Book of the Isagogue, Analytics and Categories". This contains (the first 4 are also in codex 49, which has the same title):
- The Isagogue of Porphyry, as translated by Probus, priest, archdeacon and archiater of Antioch.
- The Dialectic of Aristotle.
- The treatise of Sarguis, archiater, on the use of the Categories of Aristotle.
- The peri hermenias of Aristotle, translated from Greek to Syriac by Probus again, with a commentary by Probus.
- The abbreviated commentary on the peri hermenias, composed by Paul the Persian and translated from Persian into Syriac by Severus Sebokht.
- A letter by Severus Sebokht on the logic of Aristotle, addressed to a Yaunan, visitor.
The manuscript is undated. Whether this ms. still exists is unknown.
Works and translations
- Severus Sebokht, De Constellationibus. No complete text has ever been published.
- Complete French translation and two chapters in Syriac may be found in: F. Nau, "La Traité sur les `Constellations' Écrit, en 661, par Sévère Séboht, Évêque de Qennesrin., Revue de l’Orient Chrétien vol.27 (1929/30), pp.327-410, continued in vol.28 (1932), pp.85-100. This is a French translation of De constellationibus, with the Syriac text of chapters 4 and 5 (4 including a long portion of Aratus which is defective in our Greek mss; 5 containing Syriac astrological terms). It is prefaced with an introduction which gives the Syriac and a French translation of all the passages in Ms. Paris Syr. 346 which shed biographical light on Severus' life.
- Two other chapters of the Syriac are published from the British Library Ms. by Eduard Sachau, (1845-1930), Inedita Syriaca : eine Sammlung syrischer Übersetzungen von Schriften griechischer Profanliteratur ; mit einem Anhang, aus den Handschriften des Brittischen [sic] Museums / herausgegeben von Ed. Sachau. Publisher: Wien : K.K. Hof- und Staatsdruckerei (1870) 1 volume. (=Unpublished Syriac texts: a collection of Syriac translations of works of Greek secular literature; with a list of the mss of the British Museum).
- Severus Sebokht, On the astrolabe.
- English translation: M. Margoliouth, in R. Gunther, Astrolabes of the World. I, The Eastern Astrolabes (Oxford, 1932), 82-103. Online here. McMahon says that this is from the French.
- Syriac text and French translation: F. Nau, "Le Traité Sur l’astrolabe de Sévère Sebokht", Journal asiatique, série 9, t. xiii, 1899, P. 238-303. This was made from the Berlin Ms. Sachau 186, prior to the arrival of Ms. Paris 346 in the West. Nau subsequently published corrections in
- F. Nau, La Cosmographie au VIIe Siècle chez les Syriens, Revue de l'Orient Chrétien, vol. 5 (18) (1910) pp.225-54. A detailed description of Ms. Paris Syr. 346, including the Syriac with French translation of all the chapter titles, and of many passages, including extracts on 'Indian' (=Arabic) numerals.
- Severus Sebokht on Indian numerals: F. Nau, 'La plus ancienne mention orientale des chiffres indiens', Journal asiatique 10:16 (1910), pp.225-227. This article gives the Syriac and a French translation of the passage in Ms. Paris Syr. 346.
- Scott L. Montgomery. Science in Translation: Movements of Knowledge through Cultures and Time. Chicago: University of Chicago Press, 2000. pp. xii + 326 pp. Halftones, ISBN 0-226-53480-4.
- David Pingree's "The Teaching of the Almagest in Late Antiquity" (75-98)in Timothy D. Barnes (ed.), The Sciences in Greco-Roman Society. Aperion: A Journal for Ancient Philosophy and Science 27.4 (December 1994). Edmonton: Academic Printing & Publishing, 1994. Pp. 125. Price unspecified. ISBN 0-920980-60-0 (hb); ISBN 0-920980-61-9 (pb). Article (pp.80-95) on an anonymous commentary on Ptolemy's "Almagest" in the margins of our oldest copy -- the author concludes Severus Sebokht is the author. (From BMCR)
- Biographical Encyclopedia of Astronomers (Dordrecht: Kluwer Academic Press, forthcoming): Articles by John McMahon on Homer, Hesiod, Vergil, Ovid, Theon of Alexandria, Synesius of Cyrene, Dionysius Exiguus, Cassiodorus, and Severus Sebokht
- An account of him is included in a recently written history of Iraqi Christianity; Suha Rassan, Christianity in Iraq, Gracewing (2005). UK ISBN 0-85244-6330, p. 70. Available from Amazon.co.uk. 
- E.g. E. Renan, De philosophia peripatetica apud Syros
- M. A. Baumstark, Geschichte der syr. Literatur, Bonn (1922), pp.246-7
- This information was supplied by Steven Ring in a post to the Hugoye-L list.
- This information was supplied by Laurent Héricher, Conservateur at the BNF in response to an email query.
- F. Nau, ROC 27 (1929-30), p.327
- British Library Online Catalogue
- All this information about the ms. was supplied by email by Dr.Vrej Nersessian, the curator at the British Library.
- This information comes from an email from Dr Hartmut-Ortwin Feistel of the Orientabteilung at the Staatsbibliothek zu Berlin.
- Addai Scher, part 1, p. 498, in Journal Asiatique 1906 Juil.-déc. (Sér. 10 / T. 8). Link, under Resource