Sinhala was a kingdom in the island Lanka, modern day Sri Lanka, mentioned in the epic Mahabharata. From Sinhala Diva' (Island of Sinhala) are derived the Persian/Arabic Serendip or Sarandib, and the European 'Ceilao', 'Zeylan' and 'Ceylon'.
References in Mahabharata
The myth about the origin of the Sinhala Tribe
*Mahabharata, Book 1, Chapter 177
When the sage Vasistha was attacked by king Viswamitra's army, Vasistha's cow, Kamadehnu, brought forth from her tail, an army of Pallavas, and from her udders, an army of Dravidas and Sakas; and from her womb, an army of Yavanas, and from her dung, an army of Savaras; and from her urine, an army of Kanchis; and from her sides, an army of Savaras. And from the froth of her mouth came out hosts of Paundras and Kiratas, Yavanas and Sinhalas, and the barbarous tribes of Khasas and Chivukas and Pulindas and Chinas and Hunas with Keralas,and numerous other Mlechchhas.
In the ancient Indian literature, cow is a symbol of earth or land. Thus the myth mentioned above simply means that, these tribes gathered for the protection of sage Vasistha's land, against the army of king Viswamitra.
Kings present in Yudhisthira's Rajasuya Sacrifice
*Mahabharata, Book 2, Chapter 33
King Bhagadatta of Pragjyotisha accompanied by all Mlechcha tribes inhabiting the marshy regions on the sea-shore; and many mountain kings, and king Vrihadvala; and Vasudeva the king of the Paundrayas, and the kings of Vanga and Kalinga; and Akastha and Kuntala and the kings of the Malavas and the Andhrakas; and the Dravidas and the Singhalas and the king of Kashmira, and king Kuntibhoja of great energy and king Gauravahana, and all the other heroic kings of Valhika; and Virata with his two sons, and Mavella endued with great might; and various kings and princes ruling in various countries; and, king Sisupala accompanied by his son, all of them came to the (Rajasuya) sacrifice of Yudhisthira.
*Mahabharata, Book 2, Chapter 51
The Kings of Chola and Pandya, brought numberless jars of gold filled with fragrant sandal juice from the hills of Malaya, and loads of sandal and aloe wood from the Dardduras hills, and many gems of great brilliancy and fine cloths inlaid with gold. The king of the Singhalas gave those best of sea-born gems called the lapis lazuli, and heaps of pearls also, and hundreds of coverlets for elephants.
*Mahabharata, Book 3, Chapter 51
All kings, even those of the Vangas and Angas and Paundras and Odras and Cholas and Dravidas and Andhakas, and the chiefs of many islands and countries on the seaboard as also of frontier states, including the rulers of the Sinhalas, the barbarous mlecchas, the natives of Lanka, and all the kings of the West by hundreds, and all the chiefs of the sea-coast, and the kings of the Pahlavas and the Daradas and the various tribes of the Kiratas and Yavanas and Sakras and the Harahunas and Chinas and Tukharas and the Sindhavas and the Jagudas and the Ramathas and the Mundas and the inhabitants of the kingdom of women and the Tanganas and the Kekayas and the Malavas and the inhabitants of Kasmira, were present in obedience to your invitation, performing various offices (during Yudhisthira's Rajasuya Sacrifice). They were fighters.
Sinhalas in Kurukshetra War
*Mahabharata, Book 7, Chapter 20 The Kalingas, the Sinhalas, the Easterners, the Sudras, the Abhiras, the Daserakas, the Sakas, the Yavanas, the Kambojas, the Hangsapadas, the Surasenas, the Daradas, the Madras, and the Kalikeyas, with hundreds and thousands of elephants, steeds, chariots, and foot-soldiers were stationed at the neck of Drona's Garuda Military Formation.
- Mahabharata of Krishna Dwaipayana Vyasa, translated to English by Kisari Mohan Ganguli
- Wright, Arnold (1907) Twentieth Century Impressions of Ceylon ISBN 81-206-1335-x