2500 years ago Darius I, Great King of Persia, led an invasion army to punish the interference of some minor states beyond the western borders of his huge empire. That enemy was Athens. The resultant Battle of Marathon was a disaster for Darius and one of the most famous victories for the underdog in all military history.
The Roman Revolution is one of the most momentous periods of change in history, in which an imperial but quasi democratic power changed into an autocracy. This book studies the way the Roman army changed in the last years of the Republic, so that an army of imperial conquest became a set of rival personal armies under the control of the triumvirs.