3rd or 2nd century BCE via India, or alternatively during the 1st or 2nd century from China. Whatever the case, Mahayana Buddhism had been established by the second century CE in Vietnam. By the 9th century, both Pure Land and Thien (Zen) were major Vietnamese Buddhist schools. In the southern Kingdom of Champa, Hinduism, Theravada, and Mahayana were all practiced until the 15th century, when an invasion from the north led to the dominance of Chinese-based forms of Buddhism. However Theravada Buddhism continues to exist in the south of Vietnam. Vietnamese Buddhism is thus very similar to Chinese Buddhism and to some extent reflects the structure of Chinese Buddhism after the Song Dynasty. Vietnamese Buddhism also has a symbiotic relationship with Taoism, Chinese spirituality and the native Vietnamese religion. Korea Buddhism was introduced to the Three Kingdoms of Korea beginning around 372 CE. During the 6th century, many Korean monks traveled to China and India to study Buddhism and various Korean Buddhist schools developed. Buddhism prospered in Korea during the North–South States Period (688–926) when it became a dominant force in society. Buddhism continued to be popular in the Goryeo period (918–1392), in particular Seon (Zen) Buddhism. However, during the Confucian Yi Dynasty of the Joseon period, Buddhism faced a reversal of fortunes beginning with the confiscation of monastery lands, the closing of monasteries and the ban on ordination by aristocrats in the 15th century. Japan Buddhism was introduced to Japan in the 6th century by Korean monks bearing sutras and an image of the Buddha. During the Nara Period (710–794), emperor Shōmu ordered the building of temples throughout his realm. Numerous temples and monasteries were built in the capital city of Nara, such as the five-story pagoda and Golden Hall of the Hōryū-ji, or the Kōfuku-ji temple. There was also a proliferation of Buddhist sects in the capital city of Nara, known as the Nanto Rokushū (the Six Nara Sects). The most influential of these being the Kegon school (from the Chinese Huayan). During the late Nara, the key figures of Kūkai (774–835) and Saichō (767–822) founded the influential Japanese schools of Shingon and Tendai, respectively. An important doctrine for these schools was hongaku (innate awakening or original enlightenment), a doctrine which was influential for all subsequent Japanese Buddhism. Buddhism also influenced the Japanese religion of Shinto, which incorporated Buddhist elements. During the later Kamakura period (1185–1333), there were