The early fourteenth century marks one of the most significant periods in the development of the doctrine of the Immaculate Conception. Not only did this period witness a profound transformation in the theological understanding of the older feast of the Conception of the Blessed Virgin Mary, but it also brought about the active engagement of the laity in its celebration. In northern Italy the first lay confraternities dedicated to celebrating the feast of the Conception were founded in the 1320s and 1330s under the direction of the Franciscans, then the greatest advocates of the immaculist cause. This coincidence between the theological definition of Mary's conception, lay participation in the feast's celebration, and Franciscan sponsorship of confraternities raises interesting questions about the nature of lay piety and the role of lay associations in disseminating religious beliefs.

The question of when certain religious beliefs and their theological formulations become known and understood by the majority of the faithful is complex, particularly in the case of the Immaculate Conception. No explicit mention of Mary's sinless conception exists in Scripture or in apostolic teaching. Belief in the Immaculate Conception emerged only gradually, through centuries of reflection and disputation, and was not proclaimed a dogma of faith until 1854. This gradual unfolding of the doctrine has meant that identifying the shift from a general reverence for Mary's conception to an explicit belief in the sinlessness of her conception has proved difficult. A second difficulty is that for centuries the qualifier ‘immaculate’ was not attached to the name of the feast. During the Middle Ages the feast was referred to simply as the ‘Conception of the Blessed Virgin Mary’ The mere observance of the feast, therefore, tells us little about what the faithful actually believed.