Faith is one of history’s motors. At the same time history of the faith itself is inadequately investigated so far. Faith is not identical to religion. This notion embraces not only what people believe in (in God, saints, after-life) nut all diversity of individual and collective practices that embody this belief. Faith is a social and psychological process. In different societies people believe differently. J.-C. Shmitt, the French Historian is a specialist in the history of Middle Ages. His subject is Middle Ages. History of faith he plots is not merely history of Catholicism, institutes if the Church, sacraments and rites. He tries to understand what did it mean to believe in Middle Ages. Author raises a series of fundamental questions. What was the role of faith in medieval society? What were specific mechanisms of new beliefs' dissemination and of the Church control of the faith? Was there any place for religious doubts in the medieval culture?