Buddhism reached Korea by way of China. The religion had first come to China from India by way of the Silk Road. During the first and second centuries CE, Buddhist monks from India regularly traveled with merchant caravans and preached their religion to any who would listen. During this period, trade with China greatly increased due to relative stability in the region. Both Indian and Chinese merchants found Buddhism enticing and established and supported Buddhist monasteries along the trade routes. Eventually, these reached well into China, and it became one of the most prominent religions in the region. As Buddhism took hold in China, many Chinese monks made pilgrimages to India to study the religion at its origin. They then took what they learned back to China and helped transplant it further in their homeland.
Buddhism found its way to Korea through the efforts of Korean monks who visited China beginning in the fourth century CE. Korean tradition names Sundo as the first monk to bring Buddhism to Korea. Apparently, he was sent to Goguryeo to help forge stronger political ties with the rulers there in order to help counter the threat posed by hostile Manchurians. By creating cultural commonalities based partly on religion, the two peoples were able to unite to counter this threat. Furthermore, Buddism was partly transmitted to Korea through the efforts of an Indian monk named Marananta who came there in 384. Buddism was quickly adopted by most Korean rulers, who saw it as a way to form stronger ties with their Chinese neighbors.