According to a 2016 article by Dr. Andre Ranhel et al. published in Brazilian Journal of Cardiovascular Surgery:

“…the Middle East, especially Persia, was the birth place of a lot of intellectuals who preserved the ancient knowledge of the Greeks while building new knowledge and practices, especially from the 8^th to the 13^th century.”

[pic source slideplayer: Reforms of Cleisthenes 508 BCE… you may find “Democracy: A Persian invention” by Univ. of California’s Giulia Sissa (2012) of interest http://www.academia.edu/2172143/Democracy_a_Persian_Invention ... for educational purposes only]

According to a 2016 article by Dr. Andre Ranhel et al. published in Brazilian Journal of Cardiovascular Surgery:

“…the Middle East, especially Persia, was the birth place of a lot of intellectuals who preserved the ancient knowledge of the Greeks while building new knowledge and practices, especially from the 8^th to the 13^th century.”

[pic source slideplayer: Reforms of Cleisthenes 508 BCE… you may find “Democracy: A Persian invention” by Univ. of California’s Giulia Sissa (2012) of interest http://www.academia.edu/2172143/Democracy_a_Persian_Invention ... for educational purposes only]

Sir John Mandeville notes in his travelogue -- read and carried by Christopher Columbus -- that Trebizond was the “haven of Persians and of Medians” … 

According to the Encyclopaedia of the Hellenic World (2008), Trebizond, located in far northeastern corner of Anatolia and the southern Crimea, was a major commercial center during the 13^th century… bishops from Trebizond were allowed to visit Persia and it’s during this time that the Persian scientific tradition was introduced to Trebizond and Constantinople (Byzantine Empire)… Persian astronomy was taught and Persian manuscripts were translated to Greek in Trebizond… additionally, in Constantinople, “a Byzantine tradition inside the Persian school” was further developed in 14^th and 15^th century which spread to Western Europe…

[pic source pemptousia … for educational purposes only]