Theravada Buddhism is the largest religion in Laos, which is practiced by 66% of the population. Lao Buddhism is a unique version of Theravada Buddhism and is at the basis of ethnic Lao culture. Buddhism in Laos is often closely tied to animist beliefs and belief in ancestral spirits, particularly in rural areas. However, Laos is a multi-ethnic country with a large proportion of non-Buddhist groups that adhere to religions that are often subsumed under the denominator "animism", but that can also substantially overlap with Buddhism, or a least contain Buddhist elements resulting from cross-cultural contact. The percentage of the population that adheres to Buddhism in modern Laos is variously reported, the CIA World Factbook estimates 66% of the total population identify as Buddhist. Although this overall number is likely to be correct, there are large variations from province to province. Ethnic minority provinces like Sekong had only a quota of 20% of Buddhists in 2005, while provinces largely populated by ethnic Lao like Champassak reach 92% in the same year. There are also some Chinese or Vietnamese Mahayana Buddhists, primarily in urban centers. History Early histories of Lao Buddhism Theravada Buddhism is believed to have first reached Laos during the 7th – 8th centuries CE, via the kingdom of Dvaravati. During the 7th Century, tantric Buddhism was also introduced to Laos from the kingdom of Nan-chao, an ethnically Tai kingdom centered in modern-day Yunnan, China. The Nan-chao kingdom also likely introduced the political ideology of the king as defender and protector of Buddhism, an important ideological tie between the monarchy and the sangha in much of Southeast Asia. We also know very little about the transfer of Buddhism to the region which today is called Laos, but the current state of research suggests that Buddhism did not come in a single movement. According to Michel Lorrillard "the conditions surrounding this penetration remain very imprecise, due to the long duration of this process". From a general perspective, research on the early history of Lao Buddhism had advanced slowly, but recent studies are also signalling progress. During the 11th & 12th Century, rulers took control of Muang Sua, the historical region of the kingdom of Luang Prabang in northern Laos. During this period, Mahayana Buddhism replaced Theravada Buddhism as the dominant religious ideology of the ruling classes. Epigraphical sources confirm that the early Lao kingdoms display the first clear signs of