The Catholic Apostolic Church combined liturgical worship, charismatic experience, ecumenical vision, and eschatological expectation. Philip Schaff commented that the claims made for its apostles, if true, commanded every Christian’s attention. Historians and liturgists alike have been fascinated by the Church, but deterred from researching it because of the notorious difficulty of access to material. This account of the church’s growth and decline draws on archival sources from several countries, many not hitherto used for research, and publications in German as well as English. Previous accounts in English have focused on the Church in the English-speaking world, but this book breaks fresh ground by covering the Church’s development in every country where it was active. Surveying Catholic Apostolic history, polity, and ministry, it seeks to tell the story rather than using the Church as a test-case for a preconceived hypothesis. In so doing, it opens up a range of lines of inquiry for future researchers.