The Schwarzenau Brethren, or German Baptist Brethren as it is known in America, originated in Germany, the outcome of the Radical Pietist ferment of the late 17th and early 18th centuries. Hopeful of the imminent return of Christ, the founding Brethren abandoned the established Reformed and Lutheran churches, forming a new church in 1708 when their apocalyptic hopes were still unfulfilled. They thereby attempted to translate "the Philadelphian idea of love into concrete congregational ordinances obligatory for all the members." Unlike the Philadelphians, Brethren rejected Leade's embrace of direct revelation and emphasized early ("Apostolic" or "primitive") Christianity as the binding standard for congregational practices. The founding Brethren were also in conversation with Mennonites and influenced by Anabaptist writings.
In Germany the Brethren became known as Neue Täufer (New Baptists), in distinction from the older Baptist groups with which they had no formal ties. In the United States they became popularly known as "Dunkers", "Dunkards", or "Tunkers", forms that stem from the German verb tunken (Pennsylvanian German dunke), to dip, to immerse. Another religious group related historically to the same Radical Pietist ferment as the Brethren is the Community of True Inspiration.
The Schwarzenau Brethren was first organized in 1708 under the leadership of Alexander Mack (1679–1735) in Schwarzenau, Germany, now part of Bad Berleburg in North Rhine-Westphalia. They believed that both the Lutheran and Reformed churches were taking liberties with the "true" Christianity revealed in the New Testament, so they rejected established liturgy, including infant baptism and existing Eucharistic practices. The founding Brethren were broadly influenced by Radical Pietist understandings of an invisible, (nondenominational) church of awakened Christians who would fellowship together in purity and love, awaiting Christ's return.
A notable influence was Ernest Christopher Hochmann von Hochenau, a traveling Pietist minister. While living in Schriesheim, his home town, Mack invited Hochmann to come and minister there. Like others who influenced the Brethren, Hochmann considered the pure church to be spiritual, and did not believe that an organized church was necessary. By 1708, the date of the first Brethren baptisms, Mack had rejected this position in favor of forming a separate church with visible rules and ordinances—including threefold baptism by immersion, a Love Feast (that combined communion with feetwashing and an evening meal), anointing, and use of the "ban" against wayward members.