Short answers, pulled from the story.
The CIA World Factbook estimates that sixty-six percent of the total population of Laos identifies as Buddhist. The figure varies widely by province, ranging from twenty percent in the ethnic minority province of Sekong to ninety-two percent in Champassak in 2005.
Theravada Buddhism is believed to have first reached Laos during the seventh and eighth centuries CE, via the kingdom of Dvaravati. During the seventh century, tantric Buddhism also arrived from the kingdom of Nan-chao, an ethnically Tai state centered in present-day Yunnan, China.
The Pathet Lao reinterpreted the life of the Gautama Buddha, arguing that his rejection of royal status and wealth amounted to a revolutionary act and that his vision of a community without class distinction anticipated Marxist ideals. They also drew parallels between the Sangha's communal, propertyless life and a Marxist collective.
After the proclamation of the Lao People's Democratic Republic on the 2nd of December 1975, the traditional Sangha hierarchy was abolished and the monastic order was restructured as the Lao United Buddhists Association under Party control. By 1979, one thousand monks had reportedly been confined to re-education camps, and many others fled to Thailand.
Venerable Thammayano was the eighty-seven-year-old Supreme Patriarch of Buddhism in Laos. In March 1979, he fled to Thailand by floating across the Mekong River on a raft of inflated car inner tubes after being confined to his monastery and forbidden from preaching.
Buddhism remains central to Lao cultural identity. The Sangha continues to assist in adult literacy programs, provides traditional herbal and Western medicines in areas without doctors, and participates in HIV and drug-prevention programs. The state promotes Buddhism as national culture, and Buddhist institutes such as Champasak Sangha College teach the Dhamma, Pali, and the Buddhist canon.