On October 31, 1517, the German Priest Martin Luther posted his 95 Theses challenging the teachings of the Roman Catholic Church on the door of the church in Wittenberg. It is widely held that this act triggered the large exodus from the Catholic Church, which became known as the Protestant Reformation. Lutheranism, one of the many Protestant movements that were spawned as a result of this revolution, is largely founded on the teachings and writings of Martin Luther. The A to Z of Lutheranism sheds light on the many and varied concerns of the church, from its earliest manifestations in the 16th century to recent decisions at the turn of the 20th century. This is accomplished through a chronology, an introduction, a bibliography, an appendix, and hundreds of cross-referenced dictionary entries on important persons, major events and institutions, the theology and ethics, significant concepts, and the broader social, cultural, and economic impact of Lutheranism and its worldwide expansion.