This book develops a novel interdisciplinary approach to the phenomenon of propaganda. The key concept here is 'collective identity.' Based on this foundation, the postage stamp is systematically examined from a communication theory perspective, both as a medium in general and as a propaganda medium in particular. These fundamental considerations are ultimately illustrated using propaganda stamps from the German Empire, the Soviet Union, the People's Republic of China, and the Austrian 'Ständestaat.' As a result, a representative panorama of the propagandistic use of stamps emerges, which also aims to stimulate further research.