Data for 779 dyadic quarrels from some 300 conflicts were supplied by Rudolph Rummel and cover the time period from 1809 to 1949. A dyadic quarrel is a situation involving a pair of opponents and resulting in more than 315 human deaths. The magnitude of a quarrel is measured by the logarithm of the number of deaths. The range of magnitude in the study is from 2.50 to 7.50, the latter figure for nations involved in World War II. Each quarrel is identified by its beginning date and magnitude. For each quarrel, the nominal variables include the type of quarrel, as well as political, cultural, and economic similarities and dissimilarities between the pair of combatants.