It is moving on towards half a century now since Mestmäcker's Verwaltung, Konzerngewalt und Rechte der Aktionäre appeared. It was among the first significant postwar studies of modern corporation law in a comparative context and one that productively used his comparative mastery of American law in ways that in turn were influential in shaping the terms of reference for the 1965 reform of the Aktiengesetz. Two topics dominated his study: the treatment of conflict-of-interests transactions by managers and controlling shareholders, and the application of appropriate principles of corporation law to the affiliatedenterprise system, the Konzern. On both counts the book repays reading today; at the same time, because of the clarity of its conception and organization, it encourages the reader to reflect on what a Habilitand of today might bring back from a similar intellectual voyage.