Thanks for posting about this book LeftEyeNine, I've ordered a copy from amazon ont he strength of your reviews!

I was also having a mosey at the wikipedia page and came accross the following image of the contemporary Perisan empire:
Spoiler Alert, click show to read: 


What strikes me is that this is (to my knowledge) almost exactly the area which Alexander the Great conquered... This somewhat undermines the image I had of him demolishing a series of empires and kingdoms from Greece to the Indus, if in fact he just conquered the extents of the already vast Persia. Now I'm sure the Persian empire was goverened by a system of local proxy monarchs but my impression of his greatness was due to the expanse which he conquered and included in his empire. In effect, his empire could appear not much more dramatic than an internal coup!

Anyway, before you get the knives, chainsaws and 'bats out, this almost certainly has more to do with my lack of knowledge and misconceptions of Alexander's achievements. Also, Persia remains a big empire for (small) Macedon to conquer!