The Anabasis of Alexander (Greek: ? , Alexándrou Anábasis; Latin: Anabasis Alexandri) was composed by Arrian of Nicomedia in the second century AD, most probably during the reign of Hadrian. The Anabasis (which survives complete in seven books) is a history of the campaigns of Alexander the Great, specifically his conquest of the Persian Empire between 336 and 323 BC. Both the unusual title "Anabasis" (literally "a journey up-country from the sea") and the work's seven-book structure reflect Arrian's emulation (in structure, style, and content) of the Greek historian Xenophon, whose own Anabasis in seven books concerned the earlier campaign "up-country" of Cyrus the Younger in 401 BC.
The Anabasis is by far the fullest surviving account of Alexander's conquest of the Persian empire. It is primarily a military history, reflecting the content of Arrian's model, Xenophon's Anabasis; the work begins with Alexander's accession to the Macedonian throne in 336 BC, and has nothing to say about Alexander's early life (in contrast, say, to Plutarch's Life of Alexander). Nor does Arrian aim to provide a complete history of the Greek-speaking world during Alexander's reign. Arrian's chief sources in writing the Anabasis were the lost contemporary histories of the campaign by Ptolemy and Aristobulus and, for his later books, Nearchus. One of Arrian's main aims in writing his history seems to have been to correct the standard "Vulgate" narrative of Alexander's reign that was current in his own day, primarily associated with the lost writings of the historian Cleitarchus.
The Anabasis gives a broadly chronological account of the reign of Alexander the Great of Macedon (336-323 BC), with a particular focus on military matters. After a short Preface concerning Arrian's sources, Book 1 covers the early years of Alexander's reign (336-334 BC), including notable descriptions of Alexander's sack of Thebes in 335 and the battle of the Granicus in summer 334 BC. Book 2 is dominated by three large set-piece military operations: the campaign and battle of Issus (333 BC) and the sieges of Tyre and Gaza (332 BC). Book 3 begins with an account of Alexander in Egypt, including his visit to the oracle of Zeus-Ammon at Siwah (winter 332/331 BC), before turning to the battle of Gaugamela and defeat of Darius III (331 BC). The latter half of the book describes Alexander's pursuit of Darius through northern Iran, the revolt of the pretender Bessus, and the deaths of Philotas and Parmenion (331-329 BC). Book 4 describes the long Sogdian campaign of 329-327 BC against Bessus, Spitamenes, and Oxyartes, and the early stages of the campaigns in the Punjab (327-326 BC), with a notable departure from chronological sequence at 4.7-14, where Arrian collects many of the most notorious stories tending to Alexander's discredit in a single apologetic digression (the killing of Cleitus, the proskynesis affair, the pages' conspiracy and the death of Callisthenes). Book 5 continues the narrative of the Indian campaign of 326 BC, including Alexander's arrival at Nysa, the battle with Porus at the Hydaspes river, and the decision at the Hyphasis not to push on further into India. Book 6 describes the journey down the Indus to the Indian Ocean (326-325 BC), including the increasingly brutal violence inflicted on the local inhabitants by the Macedonians en route (notably at the Malli town), and the crossing of the Gedrosian Desert (325-324 BC). Book 7 recounts the events of Alexander's final year, including the Susa marriages, the Opis mutiny, the death of Hephaestion, and Alexander's own death (324-323 BC).
Arrian's Anabasis has traditionally been regarded as the most reliable extant narrative source for Alexander's campaigns. Since the 1970s, however, a more critical view of Arrian has become widespread, due largely to the work of A. B. Bosworth, who has drawn scholars' attention to Arrian's tendency to hagiography and apologia, not to mention several passages where Arrian can be shown (by comparison with other ancient sources) to be downright misleading.
The only complete English translation of Arrian available online is a rather antiquated translation by E.J. Chinnock, published in 1884. The original Greek text used by the Perseus Digital Library is the standard A.G. Roos Teubner edition published at Leipzig in 1907.
Probably the most widely used scholarly English translation is Loeb Classical Library edition (with facing Greek text), in two volumes. The work first appeared in 1929 and was later revised with a new introduction and appendices by P.A. Brunt in 1976.
The Landmark Ancient Histories, edited by Robert B. Strassler, includes The Landmark Arrian: The Campaigns of Alexander, edited by James Romm (Professor of Classics at Bard College, 2010), and translated by Pamela Mensch. The Landmark edition includes extensive margin notes and maps on every other page.