The book is very readable, and both non-experts and experts may find it interesting. The former can see the book as a case study of how a new area of mathematics can grow from a handful of more or less independently working mathematicians to a truly international, collaborative community, despite the difficulties of communication across the Iron Curtain... For experts, a comprehensive study of the early years of semigroup theory might shed light on some previously unnoticed connections between different branches of semigroup theory or between semigroup theory and other parts of mathematics." - Miklós Hartmann, <em>ACTA Sci. Math.</em><br /><br />"This detailed study of the history of semigroup theory is an important contribution both to the history of algebra in the 20th century and to the history of the relations between mathematicians working on both sides of the Iron Curtain." - S.C. Coutinho, <em>Mathematical Gazette</em><br /><br />"The book itself is a mixture of history and of mathematics throughout. Although the emphasis is squarely on the mathematics, there are biographies of key figures, explaining who these people were along with the occasional anecdote about their mathematical lives, reflecting their characters. For example, Lyapin was not one of the original editors of Semigroup Forum because the Soviet authorities refused him permission... Overall, this is valuable reference work, detailing much of the history of algebraic semigroups that might otherwise be lost. For connoisseurs of the subject, it represents a really good read." - <em>Mathematical Reviews</em><br /><br />"Hollings has done a masterful job. The book is well written, both in telling the story and in explaining the mathematics involved. It is an important and valuable contribution to the history of mathematics in the 20th century. This book should be in the libraries of all research institutions, and on the shelves of those interested in the history of abstract algebra, as well as those of semigroup researchers." - <em>MAA Reviews</em>