William Chester Jordan is the Dayton-Stockton Professor of History at Princeton University. His books include" Unceasing Strife, Unending Fear: Jacques de Thï¿½rines and the Freedom of the Church in the Age of the Last Capetians" (Princeton) and "Europe in the High Middle Ages".
Charles Tilly (1929-2008) was the Joseph L. Buttenwieser Professor of Social Science at Columbia University. His books include "Why?" (Princeton) and "Democracy".