King Valagamba ascended the throne in 103 AD. He waged war with the Tamils and was defeated. When he fled, a Nigantha named Giri shouted words of derisive mockery at him. Later the king collected an army attacked the Tamils by slaying the last of their leaders, and recovered the throne he had lost. It is said that he demolished Nigantaramaya (the temple of the Niganthas) and built the Abhayagiri Monastery in the same premises. Shortly after this event, the monks of the Mahavihara took disciplinary action against one of the bhikkus of the Abhayagiri Monastery for violating a rule of the vinaya. Thereafter the bhikkhus of the Abhayagiri Monastery founded a separate sect there. King Valagamba’s reign is marked by an important event – the first schism in Buddhism in Ceylon. Most learned bhikkhus lives in Abhayagiri Monastery. It consisted of a large library. It is recorded that during the reigns of King Voharakatissa and King Gothabhaya this library was destroyed and the heretical monks driven away.
Unlike its extremely conservative predecessor, the Mahavihara monastery, Abhayagiri was more open to Mahayana Buddhist influences that it used to complement its core Theravada practice. What this means from an art and architecture perspective is that Abhayagiri championed the cult of the image, catalyzing Anuradhapura’s adoption of anthropomorphic images of the Buddha and incorporating worship of these images into mainstream ritual practice. Remember, representative images of the Buddha had historically been forbidden under Theravada practice.