Symposium No. 73 of the International Astronomical Union was devoted to the obser vational and theoretical aspects of close binary stars. Just over 100 participants attended. The Local Organizing Committee would like to thank the following: IAU for travel grants. IBM United Kingdom Ltd for very generous support in the form of travel grants. The Royal Society for the provision of travel grants to participants from Eastern Europe. We also thank the Director of the Institute of Astronomy, and our colleagues and research students for their moral support and assistance. Finally we thank Pauline...

Peter P. Eggleton and James E. Pringle Institute of Astronomy Madingley Road Cambridge England The 1970's can be described, in retrospect, as the "Decade of the Close Binary". Exciting observations with new technology, combined with classical work, both observational and theoretical, convinced the astronomical world that binary interaction of various kinds is not only interesting but common. Indeed, by 1975 almost anything unusual had a good chance of being interpreted as due to binary interaction. But astronomers are seldom overwhelmed by speculation, even their own, and solid observational...