The Siamese fraternity was established in Sri Lanka in the year 1753 by a learned monk named Valivata Saranamkara under the patronage of Kirti Sri Rajasimha (1747-82).
The practice of Buddhism during this period deteriorated among the Sangha and laymen due to internal disturbances, foreign invasions, the gradual spread of Christianity and the extreme attachment of the people towards Hindu gods. Buddhist monks with higher ordination became extinct. Thus the existence of two groups of monks during this period can be identified: one group known as Ganinnanse, wearing white or saffron cloth, lived in houses close to a monastic complex with their families. The other group known as silvat-samaga - the fraternity of the pious - was engaged in the study and practice of Buddhist teachings. The latter group was headed by Saranamkara Samanera.
During the reign of king Sri Vijaya Rajasimbha (1739-47) - Kirti Sri Rajasimbha’s predecessor - the novice Saranamkara attempted twice unsuccessfully to get fully ordained monks from Thailand in order to establish higher ordination in the island. In 1750 he sent a third mission to Thailand with the assistance of Kirti Sri Rajasimbha and was able to get twenty-five monks consisting of eighteen elders (theras) and seven novices (samaneras). This group of monks was headed by the elder Upali and belonged to the lineage of orthodox Theravada tradition which was preserved by the ancient Mahavihara in Sri Lanka. They arrived in Sri Lanka in the year 1753 and performed higher ordination ceremonies in the same year within the consecrated boundaries of Malvatta and Asigiri Vihara. Thus Valivita Saranamkara and other novices were able to receive the higher ordination. King Kirti Sri Rajasimha appointed Saranamkara as the Sangharaja of the Siamese fraternity.
The fraternity at present consists of several chapters in addition to Malvatta and Asigiri Vihara, each having an administrative head (Maha Nayaka) of its own.