The Mariavites are an independent Catholic movement who were excommunicated from the Roman Catholic Church in late 1906. This book gives a history of the beginnings of the movement focusing on how the early Mariavites understood the establishment the Kingdom of God on earth (and, more precisely, in Poland). Their history dates to 1893, when the nun, Feliksa Maria Franciszka Kozlowska (1862-1921) claimed to receive revelations of Divine Mercy recommending that she she create a priests congregation of Mariavites. Due to the fraught political situation relating to the occupation of Polish lands, the Mariavites initially had to act in secret, while their mission was not accepted by the hierarchy of the Roman Catholic Church. Being outside official church structures, they introduced a number of controversial measures, especially in the interwar period after the death of their founder. Priests married nuns, nuns were ordained, compulsory confession before a priest was abolished, and finally Kozlowska was understood to be the embodiment of the Holy Spirit. These are just some of the changes that were intended to restore the state from before original sin. The Mariavites covers these and other central features of their apocalyptic or millenarian theology, including those involving the rapid exaltation of Mateczka after her death, blending of traditions associated with Mary and Jesus, and establishment of the Kingdom of God on earth through her mission. With reference to the original Polish documents, the volume clarifies for the first time the ideology, logic, motives, and theological tradition underpinning of this new religious movement. In addition, it looks at the Mariavites in the context of the influence of nineteenth-century Polish messianism, as well as the ancient Christian sources and Catholic Tradition which the Mariavites used abundantly.