The reform was designed and carried out by the king's half-brother, Prince Wachirayan, who had ordained as a monk and rose to become supreme patriarch of the whole order. Having a member of the royal house inside the monastic hierarchy solved a problem that reforming rulers elsewhere have rarely solved: the changes came from a monk of unquestioned learning rather than from a lay official, which made them far harder to resist as an intrusion by the state.
Wachirayan wrote the textbooks. He produced a graded course in the discipline and the doctrine in Thai rather than in Pali, set national examinations against it, and required monastic candidates to pass them, so that a monk in a village in the northeast studied the same material as a monk in Bangkok. He also wrote for a lay readership, and the style he established, doctrine presented in plain modern Thai and stripped of the local legendary material that had grown around it, shaped what Thai Buddhism has looked like in print ever since. Some of that legendary material has since been reclaimed by scholars as the substance of practised religion rather than as clutter.
The printing of the canon belongs to the same effort. A royal edition of the Pali texts in Thai script was produced under Chulalongkorn in the 1890s and distributed to institutions abroad as well as at home, a gesture that presented Siam as a modern state with an ancient textual tradition of its own. It was among the first printed editions of the canon produced anywhere, and it made the text portable and checkable in a way palm leaf had never allowed.