Kenkichi Iwasawa was one of the most original and influential mathematicians of the twentieth
century. He made a number of fundamental contributions in group theory and algebraic number
theory. In group theory he created the theory of (L)-groups (including the structure theorem
called Iwasawa decomposition) which played an important role in the solution of Hilbert's
Fifth Problem. In number theory he constructed a beautiful theory on Zp-extensions now called
Iwasawa theory realizing the deep analogy between number fields and algebraic function fields.
Iwasawa theory has had a strong influence on the recent development of arithmetic algebraic
geometry including the solution of Fermat's Last Theorem. This volume of the collected papers
of K. Iwasawa contains all 66 of his published papers including 11 papers in Japanese for
which English abstracts by the editors are attached. In addition the volume contains 5 papers
unpublished until 2001. Also included is a masterly summary of Iwasawa theory by J. Coates (The
University of Cambridge).
