As best as can now be estimated, over two million Cambodians died during the 1970s because of the political events of the decade, the vast majority of them during the mere four years of the “Khmer Rouge” regime. This number of deaths is even more staggering when related to the size of the Cambodian population, then less than eight million. In my estimation, about a third of the 1970 population would have survived to the end of the decade under “normal” demographic conditions but did not under the circumstances that prevailed. No single factor alone explains the rare intensity of the Cambodian mortality crisis. Instead, the excess mortality pattern reflects one of the worst imaginable mixes of conditions, including war casualties, massive population displacement, ethnic cleansing, health system collapse, and famine.

I begin this chapter with a brief summary of the various political events that had demographic consequences in the 1970s. I continue with a discussion of the different sources of data and corresponding techniques for estimating the volume of deaths during a mortality crisis. I then discuss further the estimation of the cause-of-death, sex and age patterns of crisis mortality. To illustrate how particular conditions and data availability constrain the choice of methods and the implementation of the selected methods, the last section describes past estimations of mortality patterns in Cambodia during the 1970s.