Through an examination of the Pan-German League - one of Germany's most prominent radical nationalist groups - and its connections to a range of right-wing organizations between 1918 and 1939, this study provides important new insights into the political fragmentation of the German Right and the Nazi seizure of power. It is the first book to examine in detail the Pan-German League's political activities in the Weimar and Nazi periods. Unlike existing studies that focus primarily on the League's ideology and public pronouncements, this book analyzes the organization's political connections with other prominent right-wing groups. Specifically, it explores Pan-German efforts to reshape the landscape of right-wing politics in the wake of German defeat in World War One and details how the League's actions undermined moderate conservatives and helped to radicalize Germany's largest conservative party, the German National People's Party (DNVP), at the local and national level. The book also sheds new light on the surprisingly contentious relationship between the Pan-Germans and the Nazi Party between 1920 and 1939. This study of the Pan-German League fits with more recent scholarship that emphasizes the political fragmentation of the German Right as an important precondition for the ultimate triumph of Hitler and Nazism in 1933. It will attract readers with an interest not only in the Weimar Republic and Nazi Germany, but also wider issues of German/Central European history, radical nationalism, conservative and right-wing party politics, and the general political history of interwar Europe.