Arrian

Arrian (; Greek: Ἀρριανός Arrianos; Latin: Lucius Flavius Arrianus; c. 86/89 – c. after 146/160 AD), also known as Arrian of Nicomedia, was a Greek historian, public servant, military commander, and philosopher of the Roman period.

The Anabasis of Alexander by Arrian is considered the best source on the campaigns of Alexander the Great. Scholars have generally preferred Arrian to other extant primary sources, though this attitude has changed somewhat in light of modern studies into Arrian's method.

Notable works: Epiktētou diatribai, Enchiridion of Epictetus, Anabasis of Alexander, Periplus of the Euxine Sea

Source: Wikipedia — https://en.wikipedia.org/wiki/Arrian