In this article, five members of the Goryeo royal family who became National preceptors(國師) will be examined. They lived during the middle period of the dynasty, and served the Hwa'eom-jong/華嚴宗 order when they were appointed to the seat. Hopefully their lives will reveal the relationship that existed between the state and Buddhism during that time, and help us determine the nature of that relationship.
The princes who became Buddhist priests, left the secular world to serve a religious mission that was ushered upon them, which was praying for the good fortune and prosperous future of both the state and the royal family. On the other hand, the So'gun/小君 figures, who were sons of royal concubines, were rather asked to leave for the Buddhist schools, as they frequently tended to become problems for the royal family. So while the former cases were a result of the royal family's rather active decision to ensure a better future for the royal family, the latter cases were a result of a rather defensive choosing to prevent any mishaps to occur inside the palace. Yet both cases also shared one commonality: neither of these cases were actually choices that were made voluntarily. They all followed the 'request' of the kings, who ordered them to go when they were still very young.
From the Goryeo period, total of 37 priests are confirmed to have been born from the royal family. During the middle period of the dynasty, which was from the reign of King Munjong/文宗 through the reign of King Gojong/高宗, a period which witnessed the foundation of administrative institutions for the Goryeo government, 8 princes and 20 So'gun figures left the secular world to serve Buddha. Among them, five prince-turned-priests, who were serving the Hwa'eom-jong/華嚴宗 school at the time, were named National preceptors by the kings. As it was a principle to have only one preceptor serve a single generation("一代一師"), the seat of the National preceptor was inherited from uncles to nephews, and while doing so they all tried to live in the footsteps of Master Dae'gak(大覺國師) Eui'cheon/義天(1055?1101).
The practice of having sons of the royal family leave the secular world and choose a life as a Buddhist priest was not an uncommon thing in the Asian region where Buddhism was a prospering norm. Especially in Goryeo, which had a philosophy that considered ‘Protecting the state(護國)' and 'Protecting the Buddhist teachings(護法)’ to be the same thing, the sendoff of a royal prince was regarded as the ultimate sacrifice and contribution(功德). The Goryeo people created an institution around such practice and maintained it for a long time. Not only the members of the nobility class and high-ranking governmental officials, but also gentlemen in lower statues and the people who belonged to the commoner class, all had their offsprings report to the Buddhist orders. And as a result, the social order based upon a secular social class system, came to be reflected in the operations of the Buddhist orders as well. The noble houses which were very secular in their nature, took over the overall Buddhist society and inherited their positions inside the order to other members of their own houses. Buddhism, which has always pursued universality beyond any kind of secular values, fell prey to a very much aristocratic and secular form of religion that rose in the Gaegyeong capital, during the dynasty's middle period.