ABSTRACT
King Rama V, or Chulalongkorn, was the fifth monarch of the Chakri Dynasty. He was one of the most beloved of the Thai kings due to his many activities including abolishing slavery without bloodshed and especially his skillful diplomacy which succeeded in steering Siam out of the grips of the colonial powers. His activities also included reform of the administration of the kingdom according to the European model and in bringing Siam into the modern era with such exquisite skills that he is still vividly remembered today. His reign also saw many developments in medicine and public health. The King's role in these areas, however, were clouded by his more visible activities in politics and diplomacy. The result is that the Thai public learned rather little about his role in these areas. This article aims at collecting this and to show the King's very important role in modernizing medicine and public health in Siam.