Nāgasena was a Buddhist sage who lived around 150 BCE. His answers to questions asked by Menander I (in Pali: Milinda) are recorded in the Milinda Panha.
Etymology of the name
Of Sanskrit origin, Nāga means snake, serpent, or dragon, and may also refer to snake-human hybrids, an ancient super-race that were the mythological founders of many Asian countries; Sena means army. So the name can be translated as "Army of Nāga," signifying a very powerful supernatural presence.
There is almost universal agreement that this text has been expanded by many other authors. The current version is very long, and has signs of inconsistent authorship in the later volumes.
There is no definite point at which Nagasena's authorship ends (and the work of others begins), nor has this been perceived as an inherently important distinction by scholars of religion.
The text mentions that Nagasena learned the Tripitaka from the Greek Buddhist monk Dharmarakkhita near Pātaliputta. He also achieved enlightenment and became an Arhat under his guidance.
Other personalities mentioned in the text are Nagāsena's father Soñuttara, his teachers Rohaa, Assagutta of Vattaniya, and another teacher named Āyupāla from Sankheya near Sāgala.
There is a tradition that Nagasena brought the first representation of the Buddha, the Emerald Buddha, to Thailand. According to this legend, the Emerald Buddha was created in India in 43 B.C. by Nagasena in the city of Pataliputra (now Patna).
Nagasena is not known through other sources than the Milinda Panha and this legend.
Nagasena is one of the 18 Lohans or Arhats, similar to the Apostles in Christianity. The statues show an elderly, bald monk scraping his ear with a rod, to symbolize the purification of the sense of hearing.
A devotee of Buddhism should avoid listening to gossip and other nonsense so that he is always prepared to hear the truth.