The subject of interstellar magnetic fields is of increasing interest to both observational and theoretical astronomers. Consequently, it was opportune for both groups to convene and discuss the current state of research and future prospects. For this purpose, the Max-Planck-Gesellschaft zur Forderung der Wissenschaften e.V. generously provided its unique conference centre SchloB Ringberg. The scientific organising committee consisted of Profs. W. Hillebrandt (Max-Planck-Institut fUr Physik und Astrophysik, Munchen) and R. Wielebinski (Max-Planck-Institut fUr Radioastronomie, Bonn). The lo- cal organising committee comprised Gabriele Breuer (conference secretary) and the Editors. ' These proceedings summarise the lectures and short contributions pre- sented at the workshop. Although extremely productive, the discussions could not, unfortunately, be included. We thank the staff of the castle, and especially its administrator, Mr. Hormann, for providing the excellent environment conducive to smooth run- ning of the conference. We acknowledge the Max-Planck-Gesellschaft for its support in financing the workshop. Thanks are also due to all participants for their enthusiasm and (generally!) prompt submission of manuscripts. Last but not least, we thank Gabriele Breuer for her invaluable help before, dur- ing and after the days at SchloB Ringberg. She skillfully typed and retyped many of the manuscripts for these proceedings and unstintingly performed last minute corrections. We hope that some of the ideas presented here will stimulate further discussion and research in this area. R.Beck Bonn, December 1986 R. Grave v 1 Arp, H. 15 Kundt, W. 29 Furst, E. 2 Grave, R. 16 Aly, J.J.