The battle of Issus took place in November 333 BC. After Alexander’s forces defeated the Persians at the Battle of the Granicus, Darius took personal charge of his army, gathered a large army from the depths of the empire, and maneuvered to cut the Greek line of supply, requiring Alexander to countermarch his forces, setting the stage for the battle near the mouth of the Pinarus River and south of the village of Issus. Darius was apparently unaware that, by deciding to stage the battle on a river bank, he was minimizing the numerical advantage his army had over Alexander’s.
Initially, Alexander chose what was apparently unfavorable ground. This surprised Darius who mistakenly elected to hold the wrong position while Alexander instructed his infantry to take up a defensive posture. Alexander personally led the more elite Greek Companion cavalry against the Persian left up against the hills, and cut up the enemy on the less encumbering terrain, thereby generating a quick rout. After achieving a breakthrough, Alexander demonstrated he could do the difficult thing and held the cavalry in check after it broke the Persian right. Alexander then mounted his beloved horse Bucephalus, took his place at the head of his Companion cavalry, and led a direct assault against Darius. The horses that were pulling Darius’ chariot were injured, and began tossing at the yoke. Darius, about to fall off his chariot, instead jumped off. He threw his royal diadem away, mounted a horse, and fled the scene. The Persian troops, realizing they had lost, either surrendered or fled with their hapless king. The Macedonian cavalry pursued the fleeing Persians for as long as there was light. As with most ancient battles, significant carnage occurred after the battle as pursuing Macedonians slaughtered their crowded, disorganized foe.
The Battle of Issus occurred in southern Anatolia, in November 333 BC. The invading troops led by Alexander were outnumbered more than 2:1, yet they defeated the army personally led by Darius III of Achaemenid Persia. The battle was a decisive Macedonian victory and it marked the beginning of the end of Persian power. It was the first time the Persian army had been defeated with the King present on the field. Darius left his wife and an enormous amount of treasure behind as his army fled. The greed of the Macedonians helped to persuade them to keep going, as did the large number of Persian concubines and prostitutes they picked up in the battle. Darius, now fearing for both his throne and his life, sent a letter to Alexander in which he promised to pay a substantial ransom in exchange for the prisoners of war, and agreeing to a treaty of alliance with and the forfeiture of half of his empire to Alexander. Darius received a response which began “King Alexander to Darius”. In the letter, Alexander blamed Darius for his father’s death and claimed Darius was but a vulgar usurper, who planned to take Macedonia. He agreed to return the prisoners without ransom, but told Darius that he and Alexander were not equals, and that Darius was to henceforth address Alexander as “King of all Asia”. Darius was also curtly informed that, if he wanted to dispute Alexander’s claim to the Achaemenid throne, that he would have to stand and fight, and that if he instead fled, Alexander would pursue and kill him. By this, Alexander revealed for the first time that his plan was to conquer the entire Persian Empire.