An achar (, ) or achar wat (, ) is a lay Buddhist upāsaka who becomes a ritual specialist and takes on the role of master of ceremonies in various religious rites in Cambodia.

Etymology The term achar comes from acharya (, IAST: ; Pali: acariya): in Indian religions and society, the acharya is a preceptor and expert instructor in matters such as religion, or any other subject.

Prominent acharya figures in India include Madhvacharya or Vallabhacharya.

The equivalent in Thai, ajahn, which comes from the same root, is used as an honorific title of address for high-school and university teachers, and for Buddhist monks who have passed ten vassa years in the vihāra monastery considered as "Venerable" (phra ajahn (, "venerable monk"). The footnote referenced here very usefully elaborates further on various monastic titles using ajahn. The latter is similar in meaning to the Japanese sensei.

History While the term achar has been used since Angkorian times to refer to the master of ceremonies, the figure of the achar has emerged in its contemporary form in close relationship with the movement for the Independence of Cambodia since the 19th and 20th century.

From acharya to achar: rupture and continuity with vedic sacrifices of the Angkorian period For French ethnologist Jean Moura, there is "no doubt" that the achar, like the baku, was a brahmin of earlier ages. In the historical Vedic religion, the sacrifice of fire or agnihotra in honour of Agni, the god of fire, was the simplest public rite, and the head of every Brahmin and Vaishya family was required to conduct it twice daily. In Khmer, the master of ceremonies in such occasions was known as the hotachar (ហុតាចារ្យ), corresponding to the acchāvāka of the vedic priesthood as described in the systematic expositions of the shrauta sutras,Shānkhāyana SS 13.4.1, Āsvalāyana SS 4.1.4-6. which date to the fifth or sixth century BC.

To this day, many rites, as well as occult practises, accomplished specifically by the achar in Cambodia contain various elements of brahmanism and primitive religion.

However, in modern days, many achar have rejected the vedic rites and worship of idols as unworthy of the Buddhist practitioner. Achar Ind criticizes the cult of various Brahmanical deities such as the sacred cow (Preah Ko) and grandmother Daeb (yày daeb), arguing that "since we are lay followers of the religion of the Buddha it is not right to venerate [these statues]."

The achar and the movement for the Independence of Cambodia

Since 1864 and the beginning of the French protectorate of Cambodia, the achar in Cambodia have frequently been associated with political activism, which was common for lay Buddhist scholars in other countries as well as for in example in Nepal with Dharmaditya Dharmacharya.

Insurrection of Achar Sua (1864–1866) Hardly a year after the signature of the treaty establishing the French protectorate of Cambodia, the first insurrection started led by an achar. A former monk, Achar Sua raised an army, pillaged Kampot and marched on Phnom Penh. Confronted by the troops sent against him by King Norodom, Achar Sua found refuge in a pagoda where he was killed in August 1866.

Revolt of Po Kambo or Achar Leak (1865–1867) In 1865, a more serious revolt against Norodom and his French "protectors" was incited by Po Kambo who was also known as Achar Leak. As a former monk, he gained the following of some ten thousand, including monks in robes and various holy men (neak sel) . Pou Kambo was first arrested in Tayninh on 23 April 1865. After escaping from his prison in Saigon, he rallied the support of Khmer and Cham peasants as well as Kui and Stieng minorities from the mountains in the northeast of Cambodia. Fuelled by millenarian beliefs, he gathered support by promising to rescind the confiscatory taxation policies put in place by the Protectorate. His forces killed the governor of Kratié and Sambor, 17 French soldiers. In October 1866, with more than 6,000 men, Pou Kambo defeated the royal forces near Ba Phnom and killed the Cambodian navy minister. More recruits kept coming and in November 1866, Pou Kambo marched on Oudong and Phnom Penh. On 9 January 1867, his troops attacked the Christian village of Moat Krosas in the south of Phnom Penh and assassinated Father Jean-Baptiste Barreau, beheading him and putting his head on a spike. Having rallied support at Wat Phnom, Phnom Penh, Po Kambo was forced to retread with some followers at a monastery in Kampong Thom Province where they were attacked in November 1867: Pou Kambo was eventually captured and beheaded.

Battambang uprising of 1898 and the poem of Achar Ind (1898) In 1898, cardamom collectors in Battambang Province rebelled against the high taxes imposed during the period of Thai control. The rebels were led by a certain Ta Kae and his associate, a Vietnamese magician-monk called Sau. Achar Ind, a prominent Battambang-based intellectual, praised the uprising in the popular poem The Battle of Ta Kae in the Cardamom Mountains.

Achar nationalism: between Buddhist millenarism and social conservatism The achar who encouraged the movement for the independence of Cambodia were caught between Buddhist millenarism and its violent tendency on one hand and their social conservatism on the other hand.

Thus, in 1898, in Wat Prabat Chean Chûm near Phnom Rovieng, a millienarist movement led by Ngo Prep was supported by Achar Ke. Believing that Preah Bat Thommit (the future Buddha, Maitreya) would be reborn and establish a millennial kingdom in 1899, Ngo Prep proclaimed a new unified state in which the Cambodian king and the French would serve as the future Buddha's lieutenants of the left and the right, while he would assume the role of lieutenant of the middle. The army intervened and broke into the monastery. Forty-one individuals were arrested, including two chau adhikar, with monks and achars composing a significant proportion of the total.

Yet, this activism and violence was not supported by every achar in Cambodia and it was even strongly criticized. Achar Ind, for example, looking back at the insurrections of his youth, comments that figures like the "contemptible" Po Kambo and Achar Sau were guilty of lèse-majesté. They were "awful persons [who] ... incite poor people and forest people to raise up an army to betray the king".

The Umbrella War of 1942 and the role of Achar Hiem Chieu Nationalist feeling had been rising significantly since the loss of Battambang and Siem Reap provinces to Thailand in 1941.

In response, Hem Chieu, a teacher at the École Supérieure de Pali and monk of Wat Ounalom, defended a nationalist agenda in favour of khmerization. He was the presumed leader of the Association of the Black Star (samakom phkay khmau), an occult anti-French and anti-Japanese movement with supposed links to the Issaraks and the Democratic Party. He was forcibly defrocked and arrested on July 17, 1942, as a monk could not traditionally be detained by the secular power only after first being allowed to disrobe in a ceremony organized by the sangha. More than a thousand people, around half of whom were monks, participated in the demonstration of July 20 for Hiem Chieu. Because they carried umbrellas, the event is sometimes termed the Umbrella War. Finally, he was charged with involvement in organized opposition groups and with translating seditious material from Thai. Found guilty on both charges, he was imprisoned on the penitentiary of Poulo Condor, where he died in 1943 at the age of forty-six. Having been defrocked, he was no longer a Venerable bhikkhu, but he became one of the most prominent achar of the movement toward independence.

Achar Pres seems to have fled to the Cardamom Mountains in southern Battambang immediately after the demonstrations, to "wake up the people" so that they might launch a coordinated and sustained resistance to the French.

From factionalism to communism Factionalism within the monastic order as different tendencies emerged with conflicting ideas as to the best way to defend the Khmer nation: some of the achar defending traditionalism and attachment to Buddhist values, others siding with the new-born Communist party. In June 1949, Achar Yi led a group of rebels in Kandal and Prey Veng provinces. Yi was "a quack sorcerer" according to colonial sources and he even burned Buddhist sacred writings, and in some cases the wats themselves, if he believed their monastic residents had been supporting modernization within the Mahanikay. The governor of Kandal seems to have feared that such acts of desecration might lead to wider conflict between sangha traditionalists and modernists. Nevertheless, a document of the Communist Party of Kampuchea (CPK) from the early 1970s describes Achar Yi as a "counterrevolutionary".

Also known as Achar Mean, Son Ngoc Minh had been a Pali teacher at Wat Ounalom, in Phnom Penh, and had fled to Wat Yeay Tep, in Kompong Chhnang Province, after the Umbrella War of 1942. Minh was admitted to the International Communist Party in September 1945 and by March of the following year was commanding a Vietnamese-backed resistance group in Battambang that was designed to draw French forces away from southern Vietnam. At some stage he was joined by a fellow Khmer from Kampuchea Krom called Tou Samouth, also known as Achar Sok.

Among the revolutionary groups, Achar Hiem Chieu was exalted as a martyr. In June 1950, a political school named after him was established in the southwest. A group calling itself the Achar Hem Chieu Unit was held responsible for the assassination of the governor of Prey Veng in February 1953.

Cambodia Year Zero: the persecution of the achar under the Khmers Rouges and the "new religion" From 1976 to 1979, no religious activities were allowed by the communist Khmers Rouges and the achar, as all the representatives of buddhism, were persecuted if they held on their religious practise. Some other achars however, became cadres of the Democratic Kampuchea, and even believed that they were doing the "revolution according to a new religion".

Rewriting Cambodian History to adapt it to a new political context: the achar as a national hero (1979–1991) After 1979, the Kampuchean People's Revolutionary Party began rewriting Cambodian History to adapt it to a new political context, and this included appraisal of the various nationalist achar. The Fourth Congress of the party in June 1981 resolved that "the United Front for the National Salvation of Kampuchea must be constantly enlarged and developed and must have a political line acceptable to each social layer, in particular the monks, intellectuals, the ethnic minorities." In September of the same year Ven. Tep Vong was "elected" head of a unified monastic order. Administrative posts were also created at the provincial and village levels, with village presidents effectively acting as the pre-1975 achar.

In 1982 Heng Samrin, now general secretary of the KPRP, addressed the First National Buddhist Monks Congress, at which he extolled Cambodian Buddhism as a religion in harmony with democratic principles. He also praised the positive contribution of Buddhists to society, particularly those with a nationalist outlook such as Achar Mean (Son Ngoc Minh) and Achar Hem Chieu.

In due course an official document, entitled Buddhism and the Fatherland defined the correct relationship between religion and state and among those conditions was to preserve and cultivate the patriotic and revolutionary spirit exemplified by Achar Hem Chieu and Achar Mean.

The important role of the achar in the revival of Buddhism since the fall of communism