The World Handbook of Political Indicators IV provides a set of country-level measures of contentious politics events in the tradition of the World Handbook of Social and Political Indicators (Taylor and Jodice 1983)and similar event data systems. By “contentious politics,” we mean attempts to bring about or resist political change using actions that step outside the bounds of routine politics and entail uncertainty and negative sanction. In most cases, these events center upon domestic politics and issues; but with the globalization of politics, a growing share of interactions involve international and transnational actors, issues, and targets. World Handbook IV data cover 231 countries and territories using 40 event forms to identify 263,912 events. These data comprise two files: a) a daily file; and b) an annual file. In the daily file, we provide detailed event output (date, location, actor, event form, and target), and the annual file, we provide country-year level counts for individual event forms and conceptually related groupings of event forms (i.e., civil protest, state sanction, state relaxation, and civil and state violence). In addition to the data and the codebook, this website provides documentation on how the events were coded, examples of lead lines for each event form, published and working papers, and the answers to frequently asked questions.