Mathematician:Leon the Mathematician

Mathematician
Archbishop of Thessalonike between $840$ and $843$.

Byzantine sage at the time of the first Byzantine renaissance of letters and the sciences in the $9$th century.

He was born probably in Constantinople where he studied grammar.

He later learnt philosophy, rhetoric, and arithmetic in Andros.

Made a notable contribution to the preservation and study of the writings of ancient Greek mathematicians and astronomers.

Introduced the use of the letters of the Greek alphabet for the denotation of ordinary numbers.

Constructed an optical telegraph device by means of which a chain of watch-towers could transmit not one but twelve different messages by using two accurately synchronized chronometers.

Nationality
Byzantine, but referred to himself as a Hellene.

History

 * Born: c. 790 in Constantinople, Byzantine Empire (now Turkey)
 * 835: Private tutor in Constantinople
 * 840: Consecrated Archbishop of Thessalonike by his relative the Iconomach Patriarch John VII the Grammarian.
 * 843: Forced to withdraw from his archbishopric, despite having won the respect of his flock
 * 855: Appointed director and mathematical sciences teacher at the Magnavra, one of the schools of the University of Constantinople
 * Died: c. 870

Also known as
Leon the Mathematician was also known as Leon the Philosopher.