in 372, and eventually arrived in Japan around the turn of the 6th century. For a long time Buddhism remained a foreign religion with a few believers in China. During the Tang dynasty, a fair amount of translations from Sanskrit into Chinese were done by Chinese priests, and Buddhism became one of the major religions of the Chinese along with the other two indigenous religions. In Korea, Buddhism was not seen to conflict with the rites of nature worship; it was allowed to blend in with Shamanism. Thus, the mountains that were believed to be the residence of spirits in pre-Buddhist times became the sites of Buddhist temples. Though Buddhism initially enjoyed wide acceptance, even being supported as the state ideology during the Goguryeo, Silla, Baekje, Balhae, and Goryeo periods, Buddhism in Korea suffered extreme repression during the Joseon dynasty. In Japan, Buddhism and Shinto were combined using the theological theory "Ryōbushintō", which says Shinto deities are avatars of various Buddhist entities, including Buddhas and Bodhisattvas (Shinbutsu-shūgō). This became the mainstream notion of Japanese religion. In fact until the Meiji government declared their separation in the mid-19th century, many Japanese people believed that Buddhism and Shinto were one religion. In Mongolia, Buddhism flourished two times; first in the Mongol Empire (13th–14th centuries), and finally in the Qing dynasty (16th–19th centuries) from Tibet in the last 2000 years. It was mixed in with Tengeriism and Shamanism. Sui dynasty In AD 581, Yang Jian overthrew the Northern Zhou, and established the Sui dynasty. Later, Yang Jian, who became Sui Wendi, conquered the Chen dynasty, and united China. However, this dynasty was short-lived. Sui Wendi's successor, Sui Yangdi, expanded the Grand Canal, and launched four disastrous wars against the Goguryeo. These projects depleted the resources and the workforce of the Sui. In AD 618, Sui Yangdi was murdered. Li Yuan, the former governor of Taiyuan, declared himself the emperor, and founded the Tang dynasty. Spread of Civil Service A government system supported by a large class of Confucian literati selected through civil service examinations was perfected under Tang rule. This competitive procedure was designed to draw the best talents into government. But perhaps an even greater consideration for the Tang rulers, aware that imperial dependence on powerful aristocratic families and warlords would have destabilizing consequences, was to create a body of career officials having no autonomous territorial or functional power base. As it