Mesopotamia was an abundant region between the rivers, Euphrates and Tigris, dominated by Darius more than a century earlier. The major city in this region was Babylon and was located south where Darius anticipated Alexander would lead his troops. Instead Alexander headed north in the direction of the Tigris River basically there was more food for the horses, the heat was less intense and it would also tempt Darius away from the widespread plains surrounding Babylon. Darius needed vast, flat, obstacle free areas for his chariots and cavalry to be allowed to fight effectively. Alexander knew this, hence the reason he wanted to force Darius northward where the ground would be less favourable to him. This was just one instance that shows a factor that contributed to Alexander’s triumph in the battle.
Therefore Darius moved north and encamped near the village of Gaugamela while Alexander camped a few kilometers away. Alexander managed to capture some Persian soldiers and discovered where Darius’ location was so he could observe the activities of his rival. Unlike previous battles, Darius had found a suitable battlefield and was unwilling to give this one up. The ground here was flat, perfect for