Jansenism was a branch of Catholic Gallican thought which arose in the frame of the Counter-Reformation an the aftermath of the Council of Trent (1545-1563). It emphasized original sin, human depravity, the necessity of divine grace, and predestination. Originating in the writings of the Dutch theologian Cornelius Otto Jansen, Jansenism formed a distinct movement within the Roman Catholic Church from the 16th to 18th centuries, and found its most important stronghold in the Parisian convent of Port-Royal, haven of many important theologians and writers (Antoine Arnauld, Pierre Nicole, Blaise Pascal, Jean Racine, etc.).