Reference edition:

Epistola Alexandri ad Aristotelem, ad codicum fidem edidit et commentario critico instruxit W. Walther Boer, Meisenheim am Glan 1973 (Beiträge Zur Klassichen Philologie 50).

The apocryphal letter from Alexander to Aristotle concerning the wonders of India is transmitted in a large number of codices and enjoyed a great reputation from the medieval to modern periods: it was translated into Old English around the year 1000, and subsequently—through the 15^th c.—into Irish, Icelandic, French, Middle English, and Italian.  The text is itself a translation of a lost Greek original that must have been written after the first period of the Roman Empire, since one of its contracted and partially-altered variants had already entered the Greek redaction α of the Alexander Romance (3.17 Kroll).  Latin translations of this shorter redaction were then prepared independently by the translators of the Romance: Julius Valerius (4^th c.) and the Archpresbyter Leo (10^th c.).  In 1976, Michael Feldbusch prepared a synoptic edition of the various surviving Greek and Latin redactions of the Epistola.  The fuller Latin version, with which we are concerned here, can be dated to before the 7^th c. (Boer), since a passage from it treating palus as a feminine noun (palus era sicca) is cited in the grammatical work De dubiis nominibus.  There have been attempts, chiefly on the basis of linguistic evidence, to date it to the 4^th-5^th cc. (Ruggini).  We know nothing about its author.  The content may be characterized as fantastical teratology, including hybrid and monstrous animals and people of unusual appearance or strange habits that Alexander and his army encountered while pressing into the farthest regions of the East.  Of special note are the episodes treating the battle with King Porus and the oracle given by the sun and moon’s speaking trees, which predicts Alexander’s imminent death at Babylon.  Precise sources for the stories in the Epistola have not been identified, though echoes of various Greek authors have been felt (e.g. Ctesias of Cnidus, Herodotus, Cleitarchus, and Arrian).  Alexander’s use of a disguise to sneak into Porus’ presence recalls an analogous episode in the Romance wherein he steals upon the court of Darius.  [R. Tabacco; tr. C. L. Caterine].