|The Battlefield of Gaugamela* Today|
As the Persians advanced farther and farther to the Greek flanks in their attack, Alexander slowly filtered in his rearguard. Alexander disengaged his Companions, and prepared for the decisive attack. He formed his units into a giant wedge, with him leading the charge. Behind them were the guards brigade along with any phalanx battalions he could withdraw from the battle. These were follow-up light troops. Alexander took most of his cavalry and moved parallel to Darius's front lines, heading off of the prepared battlefield. In response, Darius ordered his cavalry in the front lines to block Alexander's force. Unknown to Darius, Alexander hid a force of peltasts (light infantry armed with slings, javelins, and shortbows) behind his horsemen and slowly sent his force into an angle, heading toward the Persian host, until finally a gap opened between Bessus's left and Darius's center and Alexander sent in his cavalry to drive down the gap in the Persian line in a wedge formation. At the same time, the peltasts engaged the cavalry in order to keep them from riding back to engage Alexander's charging cavalry. The Persian infantry at the center were still fighting the phalanxes, hindering any attempts to counter Alexander's charge. WikipediaHistory geek that I am, I couldn't let the day pass without mentioning the Battle of Gaugamela (aka Arbela).
The aftermath of this battle saw the Persian Empire split in two, East and West, with Alexander controlling the Western half. It also led to the murder of the Persian Emperor, Darius III. By tradition, the Persian Empire died with Darius.
Alexander would march on to India before returning to Babylon, where he would die at the age of 32, master of a vast empire. This empire would also die, with Alexander.
Sic transit gloria mundi...