Megasthenes ( mi-GAS-thi-neez; Ancient Greek: Μεγασθένης, c. 350 – c. 290 BCE) was an ancient Greek historian, diplomat and Indian ethnographer and explorer in the Hellenistic period. He described India in his book Indika, which is now lost, but has been partially reconstructed from literary fragments found in later authors.

While Megasthenes's account of India has survived in the later works, little is known about him as a person, except that he was a Greek man. He must have been a learned man and a reputed officer, which explains his appointment as an ambassador to India. At the time of treaty between the Greek ruler Seleucus I Nicator and the Indian ruler Chandragupta Maurya in c. 303 BCE, he appears to have been serving as an officer under Sibyrtius, who was Seleucus's satrap of Arachosia.[1]

Megasthenes was a Greek ambassador of Seleucus I Nicator in the court of Chandragupta Maurya.[6] Arrian explains that Megasthenes lived in Arachosia, with the satrap Sibyrtius, from where he visited India:[2][3][5]

Megasthenes lived with Sibyrtius, satrap of Arachosia, and often speaks of his visiting Sandracottus, the king of the Indians." Arrian, Anabasis Alexandri [7]

Megasthenes visited India sometime between c. 302 and 288 BCE, during the reign of Chandragupta Maurya.[8] The exact dates of his visit to India, and the duration of his stay in India are not certain.[9] Modern scholars generally assume that Seleucus sent him to India immediately after the treaty with Chandragupta. Arrian claims that Megasthenes met Porus: this claim seems to be an erroneous one, unless we assume that Megasthenes accompanied Alexander the Great during the Greek invasion of India.[10]

Megasthenes visited the Maurya capital Pataliputra,[8] but it is not certain which other parts of India he visited. He appears to have passed through the Punjab region in north-western India, as he provides a detailed account of the rivers in this area. He must have then traveled to Pataliputra along the Yamuna and the Ganga rivers.[10]

Megasthenes compiled information about India in form of Indika, which is now a lost work, but survives in form of quotations by the later writers.

Other Greek envoys to the Indian court are known after Megasthenes: Deimachus as ambassador to Bindusara, and Dionysius, as ambassador to Ashoka.[11]

Among the ancient writers, Arrian (2nd century CE) is the only one who speaks favorably of Megasthenes. Diodorus (1st century BCE) quotes Megasthenes by omitting some parts of his narratives. Other writers explicitly criticize Megasthenes:[12]

Modern scholars such as E. A. Schwanbeck, B. C. J. Timmer, and Truesdell Sparhawk Brown, have characterized Megasthenes as a generally reliable source of Indian history.[8] Schwanbeck finds faults only with Megasthenes's description of the gods worshipped in India.[14] Brown is more critical of Megasthenes, but notes that Megasthenes visited only a small part of India, and must have relied on others for his observations: some of these observations seem to be erroneous, but others cannot be ignored by modern researchers.[13] Thus, although he was often misled by the erroneous information provided by others, his work remained the principal source of information about India to some of the subsequent writers.[1]