Abstract
This volume is a collection of papers dedicated to Kenkichi Iwasawa on his 70th birthday, which took place on September 11, 1987. Some of the papers in this volume are based on the lectures delivered at the workshop on "Iwasawa Theory and Special Values of $L$-Functions" held at the Mathematical Sciences Research Institute in Berkeley, California on January 20-24, 1987. For the convenience of the reader, a complete list of publications of Professor Iwasawa, along with brief comments on them, is added to the beginning of this volume. We hope this book will be a token of our hearty gratitude to and admiration of him, which we share with mathematicians throughout the world.