On October 1st in military history....in 331 BC

On 1st October in military history….in 331 BC. Alexander the Great of Macedonia defeats King Darius III of Persia at the Battle of Gaugamela. After crossing the Hellespont (the Dardanelles) in 334 BC and his defeats of Persian armies at the Battle of the Granicus River in May, 334 BC and the Battle of Issus in October, 333 BC, Alexander the Great spent the next two years occupying the eastern Mediterranean coast and Egypt. In 331 BC, he started advancing thru Syria toward the heart of the Persian Empire along the valleys of the Tigris and Euphrates rivers. During all this time, Darius had spent his time rebuilding his forces that he had lost at the Battle of Issus and planning for a final decisive fight with Alexander which would destroy the Macedonian. He had assembled an army (estimated around 220,000 men) which was much larger than Alexander’s. However, it was composed of mostly lightly armed infantry forces common to Persian armies. However, he did have around 200 "scythed war chariots" (a favorite weapon in Persia where the land was flat) and his cavalry forces more that outnumbered Alexander’s. Darius wanted a place where he could fight the Macedonians on his terms and where his superiority in cavalry and war chariots could be used to their fullest. He selected a flat plain (an area east of Mosul in modern Iraq) where he would wait for Alexander. To maximize his war chariots effectiveness, he ordered that brush and other vegetation be removed from the battlefield (some say that he even leveled the terrain) before the battle.

Alexander’s forces numbered around 40,000 infantry and 7,000 cavalry. However, Alexander’s forces were comprised of more heavily armed Greek hoplite infantry and Macedonian phalanxes. Alexander organized himself in a line with his general Parmenion commanding on the left flank, himself commanding on the right and phalanx infantry in the center. Due the size of the forces facing him, he would not be able to match the broad lines of Persian infantry and cavalry facing him and would most probably be out-flanked on either one or both wings. Anticipating this, he formed another line of phalanx infantry behind the first, a "double phalanx" with the instructions that the second line was to turn around if out-flanked by the Persians. Both his flanks were protected by lightly armed forces.

When the battle started, Alexander’s forces started advancing towards the Persian line, across the prepared battlefield just as Darius had planned. However, as the Macedonian forces started to moving farther into the trap laid for them, they abruptly stopped moving forward and started moving to the right (a sort-of "right oblique"). This oblique movement started moving Alexander’s forces out of prepared ground where Darius hoped to use his war chariots. Faced with a "use it or lose it" situation, Darius ordered his chariots to attack. A nasty little secret about war chariots was that although they could wreck havoc on a battlefield, they couldn’t change directions very easily and being pulled by horses, the horses tended to avoid sharp, pointy objects like walls of spears. So once a chariot got going, it was pretty well stuck in a straight line until it could slow down enough to turn. Alexander had anticipated this and had ordered gaps to open up in his lines to allow the chariots to pass thru. However, as the chariots passed thru the lines, the drivers of the chariots were attacked from the sides and killed, thereby negating the chariot’s advantages.

Darius sent his cavalry forces to encircle Alexander’s flanks, but Alexander’s forces were able to stop the encircling attacks. After awhile, Alexander’s slow rightward movement threatened to outflank Darius’ left flank, so to counter this, he ordered more of his cavalry to encircle the Alexander’s right flank. However, the cavalry protecting Alexander’s right flank was able to stop these attacks.

As more and more of Darius cavalry was committed to encircle Alexander’s right flank, a gap started to open in the line where the main Persian forces were connected with the flanking cavalry. Alexander stopped his rightward movement and turned back toward the Persian forces. Because of his rightward movement, when Alexander turned toward the Persian line, he was much closer than he normally would have been allowed to be. At this moment, the heavier Macedonian forces hit the lighter-armed Persian forces and naturally, the Persians started to give ground. Alexander and his elite Companion cavalry attacked at the gap, splitting Darius’ forces in the center from his left flank. As the Persian left flank started to disintegrate, Alexander wheeled his forces around and headed directly for Darius. The Persian center started to come apart and Darius decided that it was better "run way to live and fight another day". Estimates of casualties are that Alexander’s forces lost 10,000 killed and wounded while the Persians lost 140,000 killed and wounded. (Ed. In ancient warfare, it was very easy for the losing side to loose many more men than the victorious side due to the dynamics of masses of men being panicked. The same effect can be seen when crowds of people panic and people are trampled to death at sporting events, etc.)

King Darius later escaped to Arbil (modern Erbil) and was later killed by Bessus, one of his generals who by coincidence, was also the commander of his left flank during the battle. Alexander was crowned "King of Asia".