Thisbookisintendedasanintroductiontoallthe?nitesimplegroups.During
themonumentalstruggletoclassifythe?nitesimplegroups(andindeedsince), a
huge amount of information about these groups has been accumulated.
Conveyingthisinformationtothenextgenerationofstudentsandresearchers, not
to mention those who might wish to apply this knowledge, has become a
major challenge. With the publication of the two volumes by Aschbacher
and Smith [12, 13] in 2004 we can reasonably regard the proof of the
Classi?cation Theorem for Finite Simple Groups (usually abbreviated
CFSG) as complete. Thus it is timely to attempt an overview of all the
(non-abelian) ?nite simple groups in one volume. For expository purposes
it is convenient to divide them into four basic types, namely the
alternating, classical, exceptional and sporadic groups. The study of
alternating groups soon develops into the theory of per- tation groups,
which is well served by the classic text of Wielandt [170]and more
modern treatments such as the comprehensive introduction by Dixon and
Mortimer [53] and more specialised texts such as that of Cameron
[19].