The sanctuary has located in Anuradhapura, the capital of that time.
King Vattagamini Abhaya built the Abhayagiri Monastery and the giant Stupa or Dagaba, and He ruled Sri Lanka during the first century BC.
The term “Abhayagiri Vihara” refers not only to the complex of monastic buildings but also to a fraternity of Buddhist monks, or Sangha, which maintained its historical records, traditions, and way of life.
The stupa was named by coining the two rivals’ names, “Abaya” (The king’s name) and “Geri” (The Jain monk) – The “Abayagiri.” The circumference of this Dagaba may be roughly put down as 1,150 feet, and its original height was 400 feet.
Its significance lay, in part, in the fact that sacred and political authority were closely related, so monastic centers had much influence on the secular history of the nation. But it is also essential in the history of Theravada Buddhism itself. It was initially associated with the nearby Mahavihara (“Great Monastery”), which was the traditional center of religious and civil power built by Devananpiya-Tissa (307–267 BC). But Abhayagiri seceded from the Great Monastery toward the end of Vattagamani’s reign in a dispute over the relations between monks and the lay community and the use of Sanskrit works to augment Pali texts as scripture.
Although considered profane by the monks at the Great Monastery, the Abhayagiri monastery advanced in prestige and wealth under the patronage of King Gajabahu I (AD 113–135). Abayagiri was abandoned in the 13th century but remained intact until then. Two of its prominent colleges continued to operate until the 16th century.