After Alexander had taken control of Gaza, he fought with the king of Persia, Darius, for one last time in the Battle of Gaugamela, wherein after being defeated, Darius fled and died, resulting in the fall of the great empire.
Background
After the death of his father Philip ll in 336 BC, Alexander set out to conquer the whole of Persia. He had defeated the Persian army at the battle of Granicus and then met the Persian king, Darius lll at the battle of Issus in which he came out victorious miraculously after the battle had seemed lost.
The victory at Issus gave him hold of southern Asia Minor and he also held Darius’ mother and daughters captive while Darius was forced to draw back to Babylon where he hoped o regroup his army.
After Issus, he won the siege of Tyre which lasted almost 6 months and gave him Levant. He went on winning Gaza and the satraps of Egypt, Maxeaus surrendered peacefully.
Darius tries to negotiate with Alexander
After losing the battle of Issus, Darius tried to negotiate with Alexander. Initially he asked Alexander to leave Persia with a ransom of prisoners. He then offered his daughter in marriage but Alexander relentless.
He finally even agreed to give him half of his kingdom for peace but Alexander inspired by heroic literature of ancient Greece wanted completed surrender of Darius so that he could become the sole master of Asia.
Prelude to the battle
So unable to persuade Alexander for peace, Darius prepared for battle. While Alexander was focused on Gaza and Egypt, Darius was amassing a large army to defeat Alexander and this time Darius chose a location where the terrain was flat, where he could employ his chariots to maximum advantage and not repeat the mistake of Issus.
Alexander was actually marching for Babylon but on hearing that Darius was at Guagemala, he turned northwards to face Darius as victory almost guranteed the whole of Persia.
There seemed to be no advantages for the army of Alexander. While there are many estimates regarding the number of soldiers in each army, it is agreed upon that Darius had a clear numerical advantage.
Battle
On the eve of the battle, Alexander’s generals advised him to surprise the Persian army by an attack in the night, as that seemed the only way to win over an army so large, but Alexander refused to do so, not wanting to ‘steal a victory’.
This was a big stroke of luck, because Alexander and his army slept through the night, but the Persian Army stood alert the entire night, fearing a surprise attack, and was thus exhausted the next morning.
In this battle, Alexander used a tactic, which has rarely been used, and which required precise timing on the part of Alexander and his army. In the battle formation, Darius stood in the centre of his army, as was custom among Persians, while Alexander divided his army in two parts, in which he positioned himself at the right flank.
Firstly, the Greek army devised a new tactic to overcome the deadly chariots. When a chariot would come towards them, the first line of soldiers would step aside, leading the chariots into a trap and then both lines would effectively kill the horses and the soldiers upon it.
Selecting a precise time, Alexander led a part of his army towards the Persians to the right, in the form of a giant wedge, which attracted the soldiers around Darius towards him which then opened up a weak link in the Persian army, to kill Darius. The scythed chariots sent by Darius towards the Macedonian centre also did not have the desired effect. While Alexander spotting Darius tried to seize the opportunity. For this he hid behind his horses extra soldiers, who after Darius was left naked on one side, attacked him.
At this point it is widely believed that Darius fled the battle field and so did his army. After this, Alexander heeded to a call of help from one his generals, and decided not to pursue Darius as his left wing was almost surrounded by the Persian cavalry of the right-wing, so he supported the left wing in a decisive attack to save his army.
At this point, some parts of the Persian army broke free and tried to loot the Greek camp, and also tried to rescue Sisygambis, mother of Darius, but refused to go as she had been deserted once by Darius. It is also said that she counted as her son, only one man now, Alexander.
Aftermath
As Alexander chose to save his army rather than end the war, Darius managed to escape on horseback. After his flight his army lost morals and were soon routed by Alexander.
Darius after this defeat, planned another courageous attack on Alexander, but his soldiers and satraps had other ideas. Bessus, Darius’s relative and a satrap, killed Darius and proclaimed himself King of Persian, following which Alexander hunted him down and killed him for murdering a much respected enemy. Alexander then ordered a proper burial for Darius, at Persepolis. With this death, came the end of the Persian Empire.