Peter Turchin is a project leader at the Complexity Science Hub Vienna, a research associate at the University of Oxford, and an emeritus professor at the University of Connecticut. Trained as a theoretical biologist, he is now working in the field of historical social science that he and his colleagues call cliodynamics. Currently his main research effort is directed at coordinating CrisisDB, a massive historical database of societies sliding into crisis--and then emerging from it. His books include Ultrasociety and Ages of Discord.