The Anabasis of Alexander or The History of the Wars and Conquests of Alexander the Great is a historical account of the life and conquests of Alexander the Great, written by the Greek historian and philosopher Arrian of Nicomedia in the 2nd century AD. The work is based on the earlier histories of Alexander written by Callisthenes, Ptolemy, and Aristobulus, as well as Arrian's own personal experience as a military commander in the Roman Empire. The work is divided into seven books, each of which covers a particular period of Alexander's life and conquests. The first two books focus on Alexander's early life and his rise to power, including his ascension to the Macedonian throne and his early campaigns against the Greeks and Persians. The third and fourth books cover his conquest of Asia, including his battles against the Persian Empire and his legendary victories at Issus and Gaugamela. The fifth book describes Alexander's journey through Egypt and his conquest of the Persian capital