As a result of Alexander’s invasion of India, a number of Greek travelers came to India. They were first to communicate to the outside world what they saw of India. Famous among them are Onesicritus of Astypalaea, Aristobulus of Cassandreia and Nearchus.
Onesicritus and Nearchus ware officers in Alexander’s army during his invasion of India. Aristobulus was the Greek historian who accompanied Alexander on his campaigns.
Subsequent to these writers came the ambassadors from the Hellenistic kingdoms to the Mauryan court. Their accounts of India were based on a wider and closer observance of the country. Among them the most famous was Megasthenes, who was sent as ambassador to the court of Chandragupta Maurya by Seleucus Nikator, Alexander’s general and the Greek ruler of Persia and Babylon. Other Greek ambassadors or travelers who visited India were Deimachus, Patrocles, Dionysius and Timosthees. Deimachus came to Patliputra as ambassador to the court of Bindusara, son and successor of Chandragupta Maurya.
But none of these above mentioned writers seem to have added anything of real importance to what Megasthenes had written about India. His record of Mauryan India, compiled in Indika, has not survived to us. We learn about his record of Mauryan empire from the quotations of the later Greek writers among whom Strabo, Diodorous, Pliny the Elder, Arrian, Plutarch and Justin are notable.
Apart from the Greek sources mentioned above, the travel accounts of the famous Chinese travellers Fahien and Huen-tsang, who visited India in the 4th and 7th century AD respectively are also useful for the study of the Mauryan empire. While compiling their travelogues about India both these Chinese pilgrims referred to a number of Mauryan monuments.