This dissertation challenges the prevailing narrative in Anabaptist history and offers a fresh perspective on the regrouping of Anabaptists in the Habsburg Netherlands and adjacent German territories during the 1540s and 1550s. It disputes the widely accepted view that Menno Simons and Dirk Philips played centralized and autocratic roles in the expansion of Anabaptism during this period, arguing instead that itinerant Anabaptist bishops from the Lower Rhine region formed interconnected networks of Melchiorite and (pre-)Münsterite origin. These bishops were instrumental in expanding and connecting Anabaptist communities through coalition-building efforts, challenging the idea of Menno Simons and Dirk Philips as the primary leaders of Anabaptism in the 1540s and 1550s. The research also questions two historiographical traditions within Anabaptist/Mennonite studies. Firstly, it challenges the confessional history of Dutch Anabaptists (Mennonites) that emerged in the seventeenth century and became assimilated within the Protestant Dutch United Provinces Republic. Secondly, it questions the national perspective of nineteenth-century historiography, which often relied on an ‘invention of locality’ and confessional biases, leading to an incomplete understanding of the historical processes shaped by regional boundaries. The dissertation comprises four articles that collectively challenge the prevailing ‘small Netherlandish and ‘Menno-centric’ master narrative. The first chapter introduces a historiographical approach, while subsequent chapters focus on case studies of specific regional Anabaptist bishops from the Lower Rhine. Chapter two explores the life and contributions of itinerant Anabaptist bishop Adam Pastor, who has been largely overlooked in Mennonite historiography since the sixteenth century. It reveals Pastor’s gradual theological shift toward ‘spiritualism’ and his schism with Menno Simons and Dirk Philips over theological differences, leading to a division between Anabaptists from the Northern Netherlands ...