This Economic and Social Research Council-funded project investigates the politics of the census in societies that are deeply divided along ethnic, religious or linguistic lines, addressing some of the core themes in the Research Councils UK Cross-Council Research Programme on Global Uncertainties. In societies that are emerging from violent conflict between different ethnic, religious or linguistic groups, peace is often maintained through an agreement that these groups will share power. One of the main ways in which agreement on such power sharing is reached is through the proportional allocation of roles in government, the civil service, the military and the police to members of the groups who have been in conflict. For example, the peace agreement might specify that a certain proportion of the parliament is reserved for members of a particular minority group. In order to assess what such proportionality looks like, though, an accurate census is required. The process of conducting a census in this context can be particularly challenging, especially when group leaders know that their share of political power is partly dependent on the results. This can result in intense debates about how census questions are worded, and the conduct of the census itself may be affected by campaigns to get respondents to answer questions in particular ways, in the belief that this will influence their political representation. This aspect of the politics of the census in deeply divided societies has not been studied in significant depth by social scientists, and as a result we know little about the relationship between the design of political institutions in these societies and the likelihood of the census becoming the subject of contentious political debates. This research project addresses this lack of knowledge through examining the politics of the census in four societies that have experienced varying degrees of division along ethnic, religious or linguistic lines: Bosnia and Herzegovina, Northern Ireland, Kenya and Lebanon. In designing and conducting the project, the principal investigator has worked with policy-makers and practitioners in order to generate knowledge about how contentious political debates about the census in deeply divided societies can be mitigated, thus contributing to peaceful relations between groups that have previously been in conflict.