On October 1, 331 BC, Alexander the Great defeated Darius III of Persia in the Battle of Gaugamela." From the article:
The Battle of Gaugamela, also called the Battle of Arbela, was the decisive battle of Alexander the Great's invasion of the Persian Achaemenid Empire. In 331 BC Alexander's army of the Hellenic League met the Persian army of Darius III near Gaugamela, close to the modern city of Dohuk (Iraqi Kurdistan). Though heavily outnumbered, Alexander emerged victorious due to his army's superior tactics and his deft employment of light infantry. It was a decisive victory for the Hellenic League and led to the fall of the Achaemenid Empire.
Background,
In November 333 BC Darius III had lost the Battle of Issus, resulting in the capture of his wife, his mother and his two daughters, Stateira II and Drypetis. Darius had retreated to Babylon, where he regrouped the remaining army from the previous battle. The victory at Issus had given Alexander control of southern Asia Minor. Following a victory at the Siege of Tyre (332 BC), which lasted from January to July, Alexander controlled the Levant. After his victory at Gaza Persian troop counts were low and the Persian satrap of Egypt, Mazaeus, peacefully surrendered to Alexander.[4]
Negotiations between Darius and Alexander
Darius tried to dissuade Alexander from further attacks on his empire by diplomacy. Ancient historians provide different accounts of his negotiations with Alexander, which can be separated into three negotiation attempts.[5]
Justin, Arrian and Curtius Rufus write that Darius sent a letter to Alexander after the Battle of Issus. It demanded that he withdraw from Asia and release his prisoners. According to Curtius and Justin he offered a ransom for his prisoners, but Arrian does not mention a ransom. Curtius describes the tone of the letter as offensive.[6] Alexander refused his demands.
A second negotiation attempt took place after the capture of Tyre. Darius offered Alexander a marriage with his daughter Stateira II and all the territory west of the Halys River. Justin is less specific, not mentioning a specific daughter and speaking of a portion of Darius' kingdom.[7] Diodorus Siculus likewise mentions the offer of all territory west of the Halys River, a treaty of friendship and a large ransom for the captives. Diodorus is the only ancient historian who mentions that Alexander concealed this letter and presented his friends with a forged one favorable to his own interests. Again Alexander refused.[8]
Darius started to prepare for another battle after the failure of the second negotiation attempt. Even so, he made a third and final effort to negotiate after Alexander's departure from Egypt. Darius' third offer was much more generous. He praised Alexander for the treatment of his mother Sisygambis and offered him all territory west of the Euphrates, co-rulership of the Achaemenid Empire, the hand of one of his daughters and 30,000 talents of silver. In the account of Diodorus, Alexander deliberated this offer with his friends. Parmenion was the only one who spoke up, saying, "If I were Alexander, I should accept what was offered and make a treaty." Alexander reportedly replied, "So should I, if I were Parmenion." Alexander again refused the offer of Darius, insisting that there could be only one king of Asia. He called on Darius to surrender to him or to meet him in battle to decide who was to be the sole king of Asia.[9]
The descriptions given by other historians of the third negotiation attempt are similar to the account of Diodorus, but differ in details. Diodorus, Curtius and Arrian write that an embassy[10] was sent instead of a letter, which is claimed by Justin and Plutarch.[11] Plutarch and Arrian mention the ransom offered for the prisoners was 10,000 talents, but Diodorus, Curtius and Justin give a figure of 30,000. Arrian writes that this third attempt took place during the Siege of Tyre, but the other historians place the second negotiation attempt at that time.[12] With the failure of diplomacy, Darius decided to prepare for another battle with Alexander.
Prelude
After settling affairs in Egypt, Alexander returned to Tyre during the spring of 331 BC.[13] He reached Thapsacus in July or August.[14] Arrian relates that Darius had ordered Mazaeus to guard the crossing of the Euphrates near Thapsacus with a force of 3,000 cavalry. He fled when Alexander's army approached to cross the river.[15]
Alexander's march through Mesopotamia
After crossing the Euphrates, Alexander followed a northern route instead of a direct southeastern route to Babylon. While doing so he had the Euphrates and the mountains of Armenia on his left. The northern route made it easier to forage for supplies and his troops would not suffer the extreme heat of the direct route. Captured Persian scouts reported to the Macedonians that Darius had encamped past the Tigris River and wanted to prevent Alexander from crossing. Alexander found the Tigris undefended and succeeded in crossing it with great difficulty.[15]
In contrast, Diodorus mentions that Mazaeus was only supposed to prevent Alexander from crossing the Tigris. He would not have bothered to defend it because he considered it impassable due to the strong current and depth of the river. Furthermore, Diodorus and Curtius Rufus mention that Mazaeus employed scorched-earth tactics in the countryside through which Alexander's army had to pass.[16]
After the Macedonian army had crossed the Tigris a lunar eclipse occurred.[15] Following the calculations, the date must have been October 1 in 331 BC.[17] Alexander then marched southward along the eastern bank of the Tigris. On the fourth day after the crossing of the Tigris his scouts reported that Persian cavalry had been spotted, numbering no more than 1000 men. When Alexander attacked them with his cavalry force ahead of the rest of his army, the Persian cavalry fled. Most of them escaped, but some were killed or taken prisoner. The prisoners told the Macedonians that Darius was not far away, with his encampment near Gaugamela.[18]
Strategic analysis
Several researchers have criticized the Persians for their failure to harass Alexander's army and disrupt its long supply lines when it advanced through Mesopotamia.[19] Peter Green thinks that Alexander's choice for the northern route caught the Persians off guard. Darius would have expected him to take the faster southern route directly to Babylon, just as Cyrus the Younger had done in 401 BC before his defeat in the Battle of Cunaxa. The use of the scorched-earth tactic and scythed chariots by Darius suggests that he wanted to repeat that battle. Alexander would have been unable to adequately supply his army if he had taken the southern route, even if the scorched-earth tactic had failed. The Macedonian army, underfed and exhausted from the heat, would then be defeated at the plain of Cunaxa by Darius. When Alexander took the northern route, Mazaeus must have returned to Babylon to bring the news. Darius most likely decided to prevent Alexander from crossing the Tigris. This plan failed because Alexander probably took a river crossing that was closer to Thapsacus than Babylon. He would have improvised and chosen Gaugamela as his most favourable site for a battle.[20] Jona Lendering argues the opposite and commends Mazaeus and Darius for their strategy. Darius would have deliberately allowed Alexander to cross the rivers unopposed in order to guide him to the battlefield of his own choice.[21]
Location
Darius chose a flat, open plain where he could deploy his larger forces, not wanting to be caught in a narrow battlefield as he had been at Issus two years earlier, where he could not deploy his huge army properly. Darius had his soldiers flatten the terrain before the battle, to give his 200 war chariots the best conditions. However, this did not matter. On the ground were a few hills and no bodies of water that Alexander could use for protection, and in the autumn the weather was dry and mild.[22] The most commonly accepted opinion about the location is (36.36°N 43.25°E), east of Mosul in modern-day northern Iraq – suggested by Sir Aurel Stein in 1938 (see his Limes Report, pp. 127–1).