The ancient recorded history of Goa can be traced back as far as possible to the time of the Mauryan empire in India. The Girnar rockcut edicts of the great Mauryan emperor Ashoka of Pataliputra (Patna) refer to the people of the Konkan and their rules, as the Bhojas who were the vassals of the Maurya empire.
The Western Maurya Kingdom was made up of South Gujarat, coastal Maharashtra, Goa, and approximately half of the North Kanara district. After the Maurya Empire had passed its meridian in the 2nd century BC, its satrap in Aparanta made himself independent. A successor of the imperial Mauryas, founded a dynasty that ruled over the west coast for nearly about four centuries from its capital Shurparaka or modern Sopara. This dynasty came to be known as the Konkan Mauryas. Goa had been referred to as Sunaparant by the Mauryas.
The west coast of India was incorporated into Chandragupta Maurya’s province of Aparanta, and the impact of Magadhan Prakrit which was the official language of the Mauryan Empire, on the local dialects resulted in the formation of early Konkani, as was the case with other Aryan vernaculars. The eighth order of Ashoka discovered in Sopara indicates that during the reign of Ashoka, Buddhist missionaries were active on the West coast. Inscriptions from Goa registering the grant of land to the Buddhist Mahavira of Sivapura have been found in the copper plate of the Konkan Maurya ruler, Chandravarman (500 A.D.). The Bhoja ruler Asamkita of Hiregutti copper plate dated 475 A.D. -525 A.D., also patronized Buddhism. Monasteries were found in Colvalé, Lamgão and Rivona. During this era Buddhism was introduced to Goa.
A sculpture which has been identified as Buddha dating back to 7th Century A.D. was discovered in Rivona and was then acquired by the Goa State Museum. However, this sculpture was in a mutilated condition when found and was lacking its upper portion comprising of its head and shoulder. Hence identifying the sculpture was a difficult task and was often confused with that of Mahavir. Historians, however have been of that opinion that it could be that of Buddha due to the bhumisparsha mudra in which the image had been sculpted.
The cave in Rivona is believed to have been shelter to early Buddhists in the area. It is a huge single chamber with a large opening in the front. Standing in it gives one the feel of standing inside an open jaw. It is a laterite formation which is most likely a natural cave with some visible human interventions. Within the cave one can see a raised plinth (called Pīṭha meaning “sacred seat”), probably used by sages for meditation or preaching.
A native Goan from Rivona named Purna, also known as Punna in Pali, who is said to have been traveled to Sarnath is considered a direct disciple of Buddha, popularized Buddhism in Goa somewhere in 5th century B.C. Traces of Buddhism of the Hinayana sect, belonging to the pre-Christian era have been found at Rivona, Lamgaon, Harvalem and near Priol. According to the Buddhist text of Amavatur and Saddarmaratnakare composed in a later period, Punna, was originally a resident of Sunapurant, identified with the present Goan region from the village of Zambaulim (or Rivona?). Purna was received into the Buddhist fold by Buddha himself and helped spread that faith in this region and further south up to Ceylon.
Purna is reported to have had an impact on the people of Goa, making them a peaceful and benevolent community. It may be noted that the Buddhist monk Dharmarakshita, deputed by the emperor Asoka to the Rashtrakutas and the Bhojas from the Konkan, was a Greek convert to Buddhism.