When Buddhism was first introduced, Korea was divided into Three Kingdoms; Goguryeo (37 BCE - 668 CE), Baekje(18 BCE - 660 CE), and Silla (57 BCE - 935 CE). Buddhism was officially accepted in Goguryeo in the second year of King So-su-rim(372 CE) by the acquisition of Buddha Images and Scriptures from Venerable Sun-do, who came from Eastern Chin in China. But through private channels Buddhism was already well known to the people at that time. Goguryeo accepted Buddhism as an ideological means to control people and sanctify the power of sovereignty.

Twelve years after its introduction to Goguryeo, and Indian monk known as Maranada brought Buddhism to Baekje in the first year of King Chim-yu(384 CE). The royal court actively propagated Buddhism with the next reigning monarch, King A-shin declaring to the people that they should Obtain good fortune by believing in Buddhism. Baeje greatly contributed to the development of ancient Japan by spreading Buddhism this neighbouring land, for example King Seong-myeong sent envoys to Japan with a stone Buddha image and Buddhist scriptures. Also, Korean monks like Buddhism in Japan by visiting it and building a temple. For many centuries after this, Korean Buddhism played a significant role in the shaping of Japanese civilization. Many aspects of traditional Japanese art and culture( especially architecture, painting, ceramics, ironware, and even the famous tea ceremony) can be traced directly to the inflow of Korea a Buddhist culture into Japan at this time)

Buddhism was officially accepted in Shilla 150 years later than Goguryeo or Baekje. At first it met with great difficulties because of Shilla's weak sovereignty, and a relatively strong aristocracy who still adhered to the local religions. But on the occasion of the martyrdom of Royal Minister I-cha-don, the Shilla court finally accepted Buddhism in the 14th year of King Beob-hung's rule in 527 CE.

The reason why Buddhism could develop quickly under royal patronage of the Three Kingdoms was that, for the ancient nations, the royal authority was the center of power and Buddhism was well suited as a spiritual support for this power-base.