Arrian, also known as Flavius Arrianus, was a prominent Greek historian, public figure, and military commander of the Roman period, whose work has been invaluable to our understanding of classical antiquity, particularly concerning the campaigns of Alexander the Great. His most renowned work, 'The Anabasis of Alexander,' often simply referred to as 'The Anabasis,' provides a detailed account of Alexander the Great's ambitious conquests and the remarkable military strategies implemented during his campaigns. Drawing upon earlier sources, notably the lost works of Ptolemy and Callisthenes, Arrian's narrative is distinguishable by its rigorous methodology and lucid style, adhering to the Attic Greek tradition. His writings are considered some of the most reliable and objective when compared to those of other ancient historians covering the same topic. Beyond chronicling military events, Arrian offers insights into the character and personality of Alexander, thus contributing significantly to the historiography of the era. While 'The Anabasis' represents his most significant contribution to classical literature, Arrian's oeuvre encompasses other notable works, which collectively provide a comprehensive view of the Roman and Greek worlds during his lifetime.