This thesis examines why approximately 700 German foreign fighters traveled to Syria and Iraq between early 2012 and late 2015. It presents the author’s original research on 99 German foreign fighter profiles, examining their preexisting network connections in Germany as well as their biographical availability and integration into German society. The study finds that German foreign fighters are primarily mobilized through traditional social network connections and that the mobilizing network in Germany consists of a nationwide, interconnected, and politically active “Salafist scene.” The project also finds that while Western governments often worry about the looming threat of online radicalization, verifiable examples of purely Internet-based radicalization remain rare.