About UCDP

The Uppsala Conflict Data Program (UCDP) has recorded ongoing violent conflicts since the 1970s. The data provided is one of the most accurate and well-used data-sources on global armed conflicts and its definition of armed conflict is becoming a standard in how conflicts are systematically defined and studied.

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Lecture on Peace Research by Peter Wallensteen

The Department has recorded a lecture on the origins and developments of peace research globally and at Uppsala University with Professor Peter Wallensteen.

Watch the lecture.

About UCDP


The UCDP was properly established at the Department in the mid-1980s under the name Conflict Data Project. It continuously collects data on armed conflicts. The definitions have gradually been refined primarily to fit scholarly requirements of global comparability. The definitions are designed so as to pick up the same phenomenon across time as well as across space. This makes the data useful for systematic studies of the origins of conflict, conflict dynamics and conflict resolution. With the creation of the global conflict database (UCDP Conflict Encyclopedia), this information is now available to anyone interested in the world. However, any user should keep in mind that the ambition of a systematic data collection means that the coding rules are very strict, and that the standards are set very high for inclusion of information.

The data, furthermore, is collected on an annual basis, so that information is related to activities during one calendar year. This is so even if conflicts may start and/or end at dates that do not fit this pattern. Still, the emphasis is on the year as the basis for comparison and computation.


The Uppsala conflict data has been published, with respect to major armed conflicts, in the SIPRI Yearbook since 1988. As of 1993, a list of all armed conflicts appears in Journal of Peace Research (JPR). The time series are slightly different. In the SIPRI Yearbook it now runs from 1990. In JPR, after a joint effort with the International Institute of Peace Research, Oslo (PRIO) on backdating information, there is now data since 1946. Information on non-state conflicts has appeared in the Human Security Report since 2004. The global, online conflict database (UCDP Conflict Encyclopedia), which has the most detailed and reliable information available, covers conflicts since 1975 on a large number of variables relevant for conflict analysis. It is the broadest of all forms of publications from the UCDP. This means that there now is a dataset with data from 1946 on a limited number of variables (UCDP/PRIO dataset) and the UCDP online conflict database (UCDP Conflict Encyclopedia) with information from 1975 on a large number of variables and with detailed descriptions of the conflicts included.

The Uppsala conflict data is now a basic resource for research in many projects in the Department. The report States in Armed Conflict was published between 1987-2012.

Publication list


The activities connected with conflict data have gradually expanded. In the autumn of 2003 the amount of work on conflict data collection led to a change in the name of the project and it was thus turned into the Uppsala Conflict Data Program. This includes the regular collection of state-based armed conflicts, the global, online conflict database (UCDP Conflict Encyclopedia) as well as new forms of data relating to non-state actors and one-sided violence. Another novel aspect is the introduction of yearly fatality estimates for all conflicts, on data since 2002. Earlier there was only a broad range given. Also, issues of reconciliation, prevention, peacemaking and social impact of conflicts have led to the addition of new projects.

The latest expansion is the UCDP’s Georeferenced Event Data (GED), which is currently being coded.


The work of the conflict data program has basically rested on external funding: various research foundations and governmental agencies have extended considerable support to the work. Presently, the Bank of Sweden Tercentenary Foundation, the Swedish Research Council and Uppsala University are major contributors to the work of the program. Previously, Sida (the Swedish International Development Cooperation Agency) was a major contributor to the program. International cooperation has also gained in significance. The close connections to PRIO and HSRP (Human Security Report Project) at the Simon Fraser University in Vancouver, Canada, have generated projects for backdating conflicts as well as venturing into the issues of non-state conflicts and one-sided violence.