Callisthenes of Olynthus (in Greek Καλλισθένης; ca. 360-328 BC) was a Greek historian. He was the son of Hero and Proxenus of Atarneus, which made him the great nephew of Aristotle by his sister Arimneste. They first met when Aristotle tutored Alexander the Great. Through his great-uncle's influence, he was later appointed to attend Alexander the Great on his Asiatic expedition as a professional historian.
During the first years of Alexander's campaign in Asia, Callisthenes showered praises upon the Macedonian conqueror. As the king and army penetrated further into Asia, however, Callisthenes' tone began to change. He began to sharply criticize Alexander's adoption of oriental customs, with special scorn for Alexander's growing desire that those who presented themselves before him perform the servile ceremony of proskynesis. Having thereby greatly offended the king, Callisthenes was accused of being privy to a treasonable conspiracy and thrown into prison, where he died from torture or disease. His melancholic end was commemorated in a special treatise (Callisthenes or a Treatise on Grief) by his friend Theophrastus, whose acquaintance he made during a visit to Athens.
Callisthenes wrote an account of Alexander's expedition up to the time of his own execution, a history of Greece from the Peace of Antalcidas (387) to the Phocian war (357), a history of the Phocian war, and other works, all of which have perished. However, his account of Alexander's expedition was preserved long enough to be mined as a direct or indirect source for other histories that have survived.
A quantity of the more legendary material coalesced into a text known as the Alexander Romance, the basis of all the Alexander legends of the Middle Ages, originated during the time of the Ptolemies, but in its present form belongs to the 3rd century AD. Its author is usually known as pseudo-Callisthenes, although in the Latin translation by Julius Valerius Alexander Polemius (beginning of the 4th century) it is ascribed to a certain Aesopus; Aristotle, Antisthenes, Onesicritus and Arrian have also been credited with the authorship.
There are also Syrian, Armenian and Slavonic versions, in addition to four Greek versions (two in prose and two in verse) in the Middle Ages (see Krumbacher, Geschichte der byzantinischen Litteratur, 1897, p. 849). Valerius's translation was completely superseded by that of Leo, arch-priest of Naples in the 10th century, the so-called Historia de Preliis.