: a data set of leaders

A major reason for the relative paucity of research on leaders and international conflict was the lack of systematic data on leaders. Specifically for this book – but of much broader potential use – in collaboration with Kristian Skrede Gleditsch (University of Essex and CSCW, PRIO) we collected a new data set on leaders, entitled Archigos. Archigos ??? the Greek word for ruler ??? is a database of political leaders, specifically the effective leader of each independent state (Gleditsch and Ward, 1999) between 1875 and 2004. Initially intended as a significant extension of the temporal domain of data we compiled early on in this project (Chiozza and Goemans, 2004b), Archigos is a comprehensive revision of the earlier data with many corrections and additions. Principal sources include Lentz (1994, 1999), Keesing's, www.rulers.org and www.worldstatesman.org, and in particular for the pre-1900 leaders, Proquest Historical Newspapers (www.umi.com/proquest). Archigos is continuously updated; here we rely on Version 2.8.