This is a workmanlike little history of the career highlights of the most unlovable of the Great Captains. Unfortunately, the author has little time for context, psychological analysis or chrome of any kind: this is history by Joe Friday with "just the facts, Ma'am." Even more unfortunate is the author's appalling attempt to forgive Genghis Kahn's unbelievable atrocities (e.g., routinely and literally killing every man, woman, child, fetus, dog and cat in cities which fell to the Mongol hordes) by arguing that his acts of barbarity were no worse than those of others at that time (without providing any examples of same). This type of moral relativity is completely ridiculous and without merit, at least to me.
In any event, I am glad that this book was short since GK has to be one of the least compelling military geniuses of all time. While I recognize that most of the brilliant generals of history were unrepentant megalomaniacs, at least Alexander was personally brave and daring, Napoleon had tons of panache and style, etc. As far as I could tell from this book, GK had no redeeming qualities. He consistently double-crossed his allies, had no discernable sense of honor (e.g., he constantly went back on his word and repeatedly executed warriors and civilians who had surrendered based upon his promises of safe passage or mercy), had a Khmer Rouge-like disdain for the accoutrements of civilization and its cities, ravaged Central Asia so severely that significant parts of it have not recovered 800 years later, and created no great architecture, art or tangible legacy of any kind with all the plunder he seized. Indeed, it seems that GK was only motivated by his paranoia of internal/external threats and his lust for women (this guy must have had more sex than Wilt Chamberlain and Tiger Woods combined, apparently screwing every dead King, Kahn and candlestick maker's wife he could get his hands on).
Finally, I note that it seems that most of GK's military success was the result of the amazing disunity of his enemies, their lack of effective command and control and their employment of some of the most stupid tactics of all time. This takes nothing away from GK's incredible conquest of most of China, all of Korea, all of Central Asia, Persia, the Caucus states and lower Russia, or his defeat of every Western Army he faced in Poland, Hungary and Germany. It just makes him less enjoyable to read about than the Hannibals, Shermans or Rommels of the world.