The Chungcheong Provinces were once part of the legendary Baekje Kingdom, which was one of the Three Kingdoms of Korea (the other two are the Shilla and the Goguryeo). According to the Samgook Sagi (Chronicles of the Three Kingdoms), it was founded by King Onjo in 18 B.C. as an offshoot of the Goguryeo Kingdom. That may be correct, but what is known for sure is that the kingdom didn't become a cohesive state until sometime in the 1st century. The Baekje, who were heavily influenced by China and who helped spread Buddhism (which they adopted as their religion in 384) to this part of Korea, were by the 400s a significant trading and naval power. Unfortunately, the Shilla and Goguryeo were each eager to expand their own territory and began encroaching on the Baekje. In 660, after years of fighting, the Baekje Kingdom fell to the Shilla Kingdom, which unified the Korean peninsula for the first time. But the influence of the Baekje -- their ceramics, architecture, and spirituality -- can still be felt.