This volume summarizes recent developments in our understanding of active galactic nuclei, including quasars, seyfert galaxies and radio galaxies. The predominant emphasis is put on observational results with information from essentially all wave bands, but important theoretical results are also presented. Among the contributions are discussions of the different types of active galaxies, the nature of the central engine, the wiggly structure of radio jets, the dynamics of the gas in jets, the study of millimeter and extreme ultraviolet regions, and a discussion of the observed continuum of the entire electromagnetic spectrum. The intended readers are professional astronomers and astrophysicists as well as graduate students in this field of research.