The Pāḷi name for Thailand. There was very close relationship between Sri Lanka and Thailand from the middle ages. For details see J.R.A.S. (Sri Lanka) xxxii.190 ff.
When Buddhism fell on evil days in Sri Lanka, the kings of that Island turned to Thailand for help in the restoration of the Faith. Kittisirirājasīha obtained copies of the Mahāvaṃsa from Thailand and completed the chronicle down to his day (Cv.xcix.78 f). With the help of the Olandā (Dutch), he sent an embassy to Ayojjhā — capital of Dhammika, king of Thailand — asking that a chapter of monks might be sent to Sri Lanka. Ten monks were sent, with Upāli and Ariyamuni at their head, together with many books and other gifts. The monks took up their residence in the Pupphārāma in Sirivaḍḍhanapura (Kandy), and, under the king’s patronage, the ceremony of ordination was held on the 2296th year after the Buddha’s death, on the full-
Some time later, Dhammika again sent a chapter led by Visuddhācariya and Varañāṇamuṇi. As a token of his gratitude, Kittisirirājasīha sent to Dhammika a model of the Buddha’s Tooth Relic in Kandy, together with various other gifts. Dhammika returned his courtesy by sending various books not to be found in Sri Lanka, a replica of the Buddha’s footprint found on the Saccabaddha Mountain, etc. Cv.c.63 ff., 136 ff.