There are no known official statistics of religions in North Korea. Officially, North Korea is an atheist state, although its constitution guarantees free exercise of religion, provided that religious practice does not introduce foreign forces, harm the state, or harm the existing social order. Based on estimates from the late 1990s and the 2000s, North Korea is mostly irreligious, with the main religions being Shamanism and Chondoism. There are small communities of Buddhists and Christians. Chondoism is represented in politics by the Party of the Young Friends of the Heavenly Way, and is regarded by the government as Korea's "national religion" because of its identity as a minjung (popular) and "revolutionary anti-imperialist" movement. History Before 1945 In ancient times, most Koreans believed in their indigenous religion socially guided by mu (shamans). Buddhism was introduced from the Chinese Former Qin state in 372 to the northern Korean state of Goguryeo, and developed into distinctive Korean forms. At that time, the Korean peninsula was divided into three kingdoms: the aforementioned Goguryeo in the north, Baekje in the southwest, and Silla in the southeast. Buddhism reached Silla only in the 5th century, but it was made the state religion only in that kingdom in the year 552. In Goguryeo the Korean indigenous religion remained dominant, while Buddhism became more widespread in Silla and Baekje (both areas comprehended in modern South Korea). In the following unified state of Goryeo (918–1392), that developed from Goguryeo incorporating the southern kingdoms, Buddhism flourished even becoming a political force. In the same period, the influence of Chinese Confucianism penetrated the country and led to the formation of Korean Confucianism that would have become the state ideology and religion of the following Joseon state. The Joseon kingdom (1392–1910), strictly Neo-Confucian, harshly suppressed Buddhism and Shamanism. Buddhist monasteries were destroyed and their number dropped from several hundreds to a mere thirty-six; Buddhism was eradicated from the life of towns as monks and nuns were prohibited from entering them and were marginalised to the mountains. These restrictions lasted until the 19th century. In this environment, Christianity began to rapidly gain foothold since the late 18th century, due to an intense missionary activity that was aided by the endorsement at first by the Silhak and Seohak intellectual parties, and then at the end of the following century by the king of Korea himself and the intellectual elite of the crumbling Joseon state,