Clinicians will be familiar with the concept of taking a history to help formulate an understanding of a client to inform the intervention that will be offered. Therefore, an awareness of a country’s history, its culture, and the experience of people at various levels within that context is essential when considering how mental wellbeing can be supported. This is particularly so when one accepts that mental health and culture are entwined.
The ancient and powerful Angkorian kingdom began in AD 802 and continued until the late fourteenth century. It continues to influence Cambodians’ 
sense of identity and culture. Following the demise of this era, Cambodia entered a period of upheaval and invasions. In 1873, Cambodia became a colony and part of French Indochina. As with any colonization, there was exploitation with the indigenous population placed in a subservient position.
During the Vietnam War, the North Vietnamese and Viet Cong used parts of Cambodia as a sanctuary. America began a programme of bombing these areas, which led to the deaths of many Cambodians. Political tensions that followed loss of power by the then Cambodian government set the scene for the Khmer Rouge (Glover 2001) who took power in 1975.
The genocide led by the Khmer Rouge is well documented (Glover 2001, Van de Put and Eisenbruch 2002). Approximately two million people died— around 25% of the population. Sweeping agricultural reforms were implemented, cities were emptied of people, and attempts were made to eradicate knowledge deemed incompatible with the new regime. ‘Re-education’, the rewriting of history and cultural heritage, and the development of a culture of fear were key aspects within this process. The family structure was undermined and attempts were made to subvert individuals’ sense of the self in favour of a collective identity (Glover 2001). Among many groups that were killed were monks, educated people, trained professionals, and traditional healers. The loss of these healers dismantled the system of healing and led to a great loss of knowledge and skills.
Cambodia transformed from a traditional, family-centred Asian society into a state-centred, self-supporting communist state (Kiernan 1996). The Khmer Rouge period was a genocidal social experiment that has left a lasting legacy. It continues to have a profound impact on the psyche, culture, and environment of Cambodians.
In 1978, the Vietnamese Army invaded Cambodia. In 1989, a peace process began, reaching a ceasefire in 1991. The Khmer Rouge remained a strong guerrilla force up until the late 1990s, surrendering in 1998.
-  TPO will be used throughout this chapter to refer to TPO Cambodia.