ABSTRACT To further our understanding of the transformations of the modern, globalized world, historical research concerning the twentieth century must acknowledge the tremendous impact that science and technology exerted and continue to exert on political, economic, military, and social developments. To better comprehend a global history of science, it is also crucial to include Germany’s most prominent research organization: The Max Planck Society for the Advancement of Science (MPG). Despite the existence of numerous institute chronicles and selected anniversary editions, the overall development of the MPG—historically situated in more than 80 institutes with more than 250 research service departments (of which approximately 50 have reached into the wider field of neuroscience, behavioral science, and cognitive science)—it remains largely terra incognita from a scholarly perspective. From June 2014 to December 2022, the Research Program on the History of the Max Planck Society (GMPG) opened previously neglected vistas on contemporary history, academic politics, and economic developments of the Federal Republic of Germany and its international relations by raising questions such as these: Who were the key scientific actors? In what networks did they work? In what fields had the MPG paved the way for cutting-edge innovations? What were its successes and where did it fail? In what ways were its institutional structures connected to its scientific achievements and its historical legacies? What is specific about the MPG in comparison to other national institutions in and outside of Germany? These questions relate to the emerging interdisciplinary field of the neurosciences. They refer in part to the MPG’s founding years—from the late 1940s to the mid-1960s—which faced significant challenges for a “normalization process” in biomedical research and the burgeoning field of neuroscience. This special issue of the Journal of the History of the Neurosciences is composed of an introduction, five articles, and two neuroscience history interviews. It reflects on the multifold dimensions of behavioral psychology, brain research, and cognitive science developments at the MPG since its beginning through the reopening of several former Kaiser Wilhelm Institutes. After World War II, the extra-university research society—named in honor of physicist Max Planck (1858–1947)—was eventually established in the British Occupation Zone in 1946, in the American Zone in 1948, and in 1949 in the French Zone, unifying the MPG as the successor umbrella organization of the Kaiser Wilhelm Institutes (KWIs), now transformed into Max Planck Institutes. Chronologically, the research period covered in this special issue ranges from 1948 to 2002.