Between the early 14th century and the first thirty years of the 16th century, beliefs and practices about the Virgin Mary in Sweden undergo an evolution which, while increasing the integration of the country into European space, also singularizes it by its characteristics. For example, the influence of Saint Bridget of Sweden is considerable. As mystic and a particularly zealous devotee of the Mother of God, Bridget founded in Vadstena a monastery and a religious order whose influence is crucial on Swedish spirituality. Using primary sources produced by Bridget and her spiritual heirs, as well as those concerning the worship of the Virgin Mary in a more general perspective, this dissertation aims at documenting the major influence of Bridgettine spirituality on the religiosity of the Swedes at the end of the Middle Ages. The specificity of the Swedish Marian cult are studied on different scales: from the monastery of Vadstena to the dioceses, thanks to liturgical sources. The modalities of diffusion of Marian celebrations are studied as well as the transmission of dogmatic contents. If the methodology used in this dissertation is mainly the one of the historian, it does not rule out a temporary use of tools developped by other discipline, and especially Cognitive Sciences.