King of Ceylon (247-207 B.C.). He was the second son of Mutasīva. It is said that on the day of his coronation many wonderful treasures miraculously appeared, some of which he resolved to send as tokens of esteem to his contemporary Dhammāsoka of India, with whom he had long been on terms of friendship. An embassy, led by his nephew Mahārittha, was despatched to Pātaliputta, and the emperor showed the ambassadors every mark of honour. He sent back with them all the requisites for a coronation, with instructions to celebrate the inauguration of the Sinhalese king, whom he invited to embrace Buddhism. On the return of the embassy, the king was solemnly crowned a second time. This confirmation of Devānampiyatissa's sovereignty under the aegis of Asoka may have been due either to the commanding position of Asoka or for the strengthening of family connections. Asoka was a Moriyan (a branch of the Sākiyans) and Devānampiyatissa had Sākiyan blood.
The chief event in the reign of Devānampiyatissa was the arrival of Mahinda in Ceylon. He arrived at the head of a mission in the year of the king's second coronation. Mahinda met the king hunting on the full-moon day of Jettha. The king welcomed him with great honour and speedily embraced the new religion, to which Asoka had already drawn his attention.
His conversion was the direct result of Mahinda's preaching of the Cūlahatthipadopama Sutta. His earlier religion is not known, it may have been Jainism. His example was followed by a large number of his subjects, many of whom entered the Order. Devānampiyatissa dedicated to their use the Nandana park and the Mahāmeghavana, which he himself had laid out a little earlier. In the Mahāmeghavana he built the famous Mahā-Vihāra which, for many centuries, remained the centre of the orthodox religion in Ceylon. The dedication of the Mahā-Vihāra took place in the two hundred and thirty-sixth year after the death of the Buddha. The king's next pious work was the erection of the Cetiyapabbata-vihāra and he, later, built the Thūpārāma, containing the Buddha's right collar-bone.
When the women of the palace, led by Anulā, wife of the sub-king, Mahānāga, expressed a desire to become nuns, Devānampiyatissa sent another embassy to Asoka asking him to send Sanghamittā, together with the right branch of the sacred Bodhi-tree. This branch miraculously severed itself from the parent tree and, together with Sanghamittā, was conveyed down the Ganges and arrived in Jambukola, where it was received with all honour by Devānampiyatissa. From Jambukola it was taken in procession to Anurādhapura, where it was planted in the Mahāmeghavana, the king instituting in its honour a festival, which was observed for many centuries. For the use of Sanghamittā and the nuns the king erected various buildings, the chief of which was the Hatthālhaka-vihāra and the Upāsikā-vihāra with its twelve mansions. (This account is summarised from the Mahāvamsa (chaps.xi., xiii.-xx.); also Dpv.xi.14ff; xii.7; xvii.92).
Among other works of Devānampiyatissa we are told of the building of the Issarasamana- and the Vessagiri-vihāras, the refectory called Mahāpāli, the Jambukola-vihāra in Nāgadīpa, the Tissamahā-vihāra, the Pācīnārāma and the Pathamathūpa. He also built the Tissavāpi at Anurādhapura. (The Cv. (xxxvii.94) mentions also the Dhammacakka as having been built by Devānampiyatissa. It later became the Temple of the Tooth at Anurādhapura).
Mahinda survived him by eight years. Devānampiyatissa seems to have died without issue, for he was succeeded by four of his brothers.