"the successful expedition of Alexander related by Arran"
Lucius Flavius Arrianus 'Xenophon' (ca. AD 86 - 160), known in English as Arrian, was an historian, public servant, military commander and philosopher in 2nd
century Rome. Anabasis of Alexander
is his best known work, generally considered one of the best sources on the campaigns of Alexander the Great. Arrian was able to use sources which are now mostly lost, including contemporary works by authors such as Callisthenes, the nephew of Alexander's tutor Aristotle. Arrian also had the biography of Alexander by Ptolemy, one of Alexander's leading generals and allegedly his half-brother.