King of Ceylon (29 17 B.C.). He was the son of Saddhātissa, and came to the throne by killing the usurper Mahārattaka (v.l. Kammahārattaka).
He married Anulā, wife of Khallātanāga, and adopted Mahācūlika as his own son; because of this Vattagāmanī came to be known as Pitirājā (this name occurs several times in the Commentaries - e.g., VibhA. passim, see Pitirājā).
Vattagāmanī had a second wife, Somadevī, and also a son of his own, called Coranāga. In the fifth month of his reign a brahmin, named Tissa, rose against him, but was defeated by seven Damilas who landed at Mahātittha. . After that, the Damilas waged war against the king and defeated him at Kolambālaka. It was a remark made by the Nigantha Giri to Vattagāmainī, as he fled from the battle, that led later to the establishment of Abhayagiri (q.v.). The king hid in the forest in Vessagiri and was rescued by Kupikkala Mahātissa, who gave him over to the care of Tanasīva. In his flight he left Somadevī behind, and she was captured by the Damilas.
For fourteen years Vattagāmanī and his queen Anulā lived under the protection of Tanasīva, and, during this time, five Damilas ruled in succession at Anurādhapura; they were Pulahattha, Bāhiya, Panayamāra, Pilayamāra and Dāthika.
After a time, Anulā quarrelled with Tanasīva's wife, and the king, in his resentment, killed Tanasīva. Later, when he also killed Kapisīsa, his ministers left him in disgust, but were persuaded by Mahātissa to return. When his preparations were complete, the king attacked Dāthika, slew him, and took the throne. He then founded Abhayagiri-vihāra and recovered Somadevī. He also built the Silāsobbhakandaka-cetiya. He had seven ministers who themselves built several vihāras; among them Uttiya, Mūla, Sāliya, Pabbata and Tissa are mentioned by name.
It was in the reign of Vattagāmanī that the Buddhist Canon and its Commentaries were first reduced to writing in Ceylon, according to tradition, in Aloka vihāra. For details of Vattagāmanī's reign see Dpv.xx.14ff.; Mhv.xxxiii.34ff. The foundation of Abhayagiri vihāra formed the beginning of dissensions in the ranks of the monks (Cv.lxxiii.18). Vattagāmani was, however, regarded by later generations as a great protector of the faith (Cv.lxxxii.23). Various monasteries, chiefly rock temples, are traditionally ascribed to Vattagāmanī, and said to have been built by him during his exile; among these is the modern Dambulla vihāra. The Cūlavamsa calls him the founder of the Majjhavela vihāra. Cv.c.229.