Structured along the lines of the "big man-style of history" (i.e. Euclid,Descrates, Gauss, Einstein and Edward Witten) this book takes us from theGreeks to Superstring (M-Theory) of the present. The explanations arevery clear and the historical elements are interesting and concise. In a book of this size it can only be an introduction, of course, but itvery readable and contains mathematical details, where justified. I would recommend The Elegant Universe by Brian Greene as an excellentcontinuation to the later chapters on Superstring and M-Theory.