Leo the Mathematician

Leo was born in Thessaly, a cousin of the Patriarch of Constantinople, John the Grammarian. Little is known about his early life.{{efn|There are speculations that Leo was of Armenian ancestry, but these claims have been challenged.{{sfn|Bromige|2023|p=22: "Shirinian identifies many influential Byzantines in the mid-ninth century, such as Photios, John the Grammarian and Leo the Mathematician, as Armenian in origin, but these claims have been challenged"}} There is a tendency amongst certain Byzantinists to propose an "Armenian" ancestry for certain Byzantine individuals and/or families with an obscure heritage as a "convenient solution",{{sfn|Bryer|1980|p=165}} even if the evidence is flimsy, non-existent or completely fictional.{{sfn|Kaldellis|2019|p=155-195}}}} In his youth he was educated at Constantinople, but found higher education options limited in the city and thus travelled to the monasteries of Andros, where he could obtain rare manuscripts and was taught mathematics by an old monk.{{cite journal |last=Browning |first=Robert |year=1964 |title=Byzantine Scholarship |journal=Past and Present |issue=28 |pages=7–8 |doi=10.1093/past/28.1.3}}{{Cite book |last=Lemerle |first=Paul |title=Byzantine Humanism: The First Phase: Notes and Remarks on Education and Culture in Byzantium from Its Origins to the 10th Century |publisher=Brill |year=2017 |location=Leiden |pages=172 |language=English |translator-last=Helen |translator-first=Lindsay}} He originally taught privately in obscurity in Constantinople. The story goes that when one of his studentsAccording to the Pseudo-Symeon, this student was Boïditzes, who betrayed Amorium to the caliph. was captured during the Byzantine–Arab Wars, the Caliph al-Mamun was so impressed by his knowledge of mathematics, providing proofs that his own scholars were unable to complete, and predictive abilities that he offered Leo great riches to come to Baghdad.According to Joseph Genesius and Theophanes Continuatus between 829 and 833; Symeon the Logothete makes the caliph al-Mutasim and puts the invitation after the Islamic conquest of Amorium in the fall of 838, cf. {{cite journal |last=Treadgold |first=Warren T. |year=1979 |title=The Chronological Accuracy of the Chronicle of Symeon the Logothete for the Years 813–845 |journal=Dumbarton Oaks Papers |volume=33 |pages=162 |doi=10.2307/1291437|jstor=1291437 }} Leo took the letter from the caliph to the Byzantine emperor Theophilos, who, impressed by his international repute, conferred on him a school (ekpaideutērion) in either the Magnaura or the church of the Forty Martyrs.Symeon says the Magnaura, Continuatus the Forty Martyrs (Treadgold, "Chronological Accuracy ", 186).

In the version of the story recorded by Theophanes Continuatus, the caliph, upon receiving Leo's letter of refusal, sent a letter requesting answers to some difficult questions of geometry and astrology, which Leo obliged. Al-Mamun then offered two thousands pounds of gold and a perpetual peace to Theophilos, if only he could borrow Leo's services briefly; the request was declined. The emperor then honoured Leo by having John the Grammarian consecrate him metropolitan of Thessalonica, which post he held from the spring of 840 to 843. There is a discrepancy in this account, however, in that the caliph died in 833. It has been suggested that either the connection between the caliph's final letter and Leo's appointment as metropolitan is in error, or the caliph in question was actually al-Mutasim. This latter option squares with the account of Symeon the Logothete, who makes Leo teach at the Magnaura from late 838 to early 840 and was paid handsomely.Treadgold, "Chronological Accuracy ", 172.

Leo, an iconoclast sometimes accused of paganism, lost his metropolitancy with the end of the Iconoclasm in 843.Warren T. Treadgold (1997), A history of the Byzantine state and society (Stanford University Press), 447. Despite this, he delivered a sermon favourable of icons within months of Theophilos' death.Warren T. Treadgold (1988), The Byzantine Revival, 780–842 (Stanford University Press), 372. Around 855, Leo was appointed at the head of a newly established Magnaura School by Bardas.Treadgold, "Chronological Accuracy ", 187, believes, on the basis of the Logothete's account, that this occurred in 843 and was a re-founding of Theophilos' school. He was renowned for his philosophical, mathematical, medical, scientific, literary, philological, seismological, astronomic, and astrological learning, and was patronised by Theoktistos and befriended by Photios I of Constantinople.{{cite book |title=The Reign of Leo VI (886–912): Politics and People |last=Tougher |first=Shaun |year=1997 |publisher=Brill |location=Leiden |isbn=90-04-10811-4 |page=113 }}{{cite book |title=The Entry of the Slavs into Christendom: An Introduction to the Medieval History of the Slavs |last=Vlasto |first=A. P. |year=1970 |publisher=Cambridge University Press |location=Cambridge |page=33 }} Cyril was his student. Leo has been credited with a system of beacons (an optical telegraph) stretching across Asia Minor from Cilicia to Constantinople, which gave advance warning of Arab raids, as well as diplomatic communication.{{cite journal |last=Treadgold |first=Warren T. |year=1979 |title=The Revival of Byzantine Learning and the Revival of the Byzantine State |journal=The American Historical Review |volume=84 |issue=5 |pages=1245–1266 [p. 1259] |doi=10.2307/1861467|publisher=American Historical Association |jstor=1861467 }} Leo also invented several automata, such as trees with moving birds, roaring lions, and a levitating imperial throne. The throne was in operation a century later, when Liutprand of Cremona witnessed it during his visit to Constantinople.{{cite book |title=Heaven on Earth: Art and the Church in Byzantium |last=Safran |first=Linda |year=1998 |publisher=Penn State Press |location=Pittsburgh |isbn=0-271-01670-1 |page=30 }} Records Liutprand's description.For a detailed discussion of Leo's telegraph and his automata, see Leone Montagnini (2002), [http://www.armoniedeldisordine.it/opere.html#02i "Leone il Matematico, un anello mancante nella storia della scienza"], {{Webarchive|url=https://web.archive.org/web/20131017235629/http://www.armoniedeldisordine.it/opere.html#02i |date=2013-10-17 }} Studi sull'Oriente Cristiano, 6 (2), 89–108.

Most of Leo's writings have been lost. He wrote book-length works, poems, and many epigrams,Among them are some centos preserved in the Palatine Anthology; see Prieto Domínguez, Óscar (2011), De Alieno Nostrum: el Centón profano en el mundo griego. Estudios Filológicos, 328. Salamanca: Ediciones Universidad de Salamanca. {{ISBN|9788478002085}}, p. 120-179. and was also a compiler, who brought together a wide range of philosophical, medical, and astronomic texts. His library can at least partially be reconstructed: Archimedes, Euclid, Plato, Paul of Alexandria, Theon of Alexandria, Proclus, Porphyry, Apollonius of Perga, the lost Mechanics of Quirinus and Marcellus, and possibly Thucydides. He composed his own medical encyclopaedia. Later Byzantine scholars sometimes confused Leo with the scholar Leo Choirosphaktes and the emperor Leo VI the Wise, and ascribe to him oracles.

Recent years have seen the first translations into English of a number of primary sources about Leo and his times.

• Featherstone, Jeffrey Michael and Signes-Codoñer, Juan (translators). Chronographiae quae Theophanis Continuati nomine fertur Libri I-IV (Chronicle of Theophanes Continuatus Books I-IV, comprising the reigns of Leo V the Armenian to Michael III), Berlin, Boston: De Gruyter, 2015.
• Kaldellis, A. (trans.). On the reigns of the emperors (the history of Joseph Genesios), Canberra: Australian Association for Byzantine Studies; Byzantina Australiensia 11, 1998.
• Ševčenko, Ihor (trans.). Chronographiae quae Theophanis Continuati nomine fertur Liber quo Vita Basilii Imperatoris amplectitur (Chronicle of Theophanes Continuatus comprising the Life of Basil I), Berlin: De Gruyter, 2011.
• Wahlgren, Staffan (translator, writer of introduction and commentary). The Chronicle of the Logothete, Liverpool University Press; Translated Texts for Byzantinists, vol. 7, 2019.
• Wortley, John (trans.). A synopsis of Byzantine history, 811-1057 (the history of John Scylitzes, active 1081), Cambridge University Press, 2010.

{{Notelist}}

• {{Cite book |last=Bromige |first=Toby |title=Armenians in the Byzantine Empire: Identity, Assimilation and Alienation from 867 to 1098 |date=2023 |publisher=I.B. Tauris |isbn=978-0-7556-4242-7 |language=en}}
• {{Cite book |last=Bryer |first=Anthony |title=The Empire of Trebizond and the Pontos |date=1980 |publisher=Variorum Reprints |isbn=978-0-86078-062-5 |language=en}}
• {{Cite book |last=Kaldellis |first=Anthony |title=Romanland: Ethnicity and Empire in Byzantium |date=2019 |publisher=Harvard University Press |isbn=978-0-674-98651-0 |language=en}}

{{reflist|2}}

• Katerina Ierodiakonou and Börje Bydén (2008), [http://plato.stanford.edu/entries/byzantine-philosophy/#PeoWorCur "Byzantine Philosophy."] Stanford Encyclopedia of Philosophy.

{{Bishops of Thessalonica}}

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{{DEFAULTSORT:Leo the Mathematician}}

Category:790s births

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