The stronghold at Gaza was built on a hill and was heavily fortified. The inhabitants of Gaza and their Nabataean allies did not want to lose the lucrative trade which was controlled by Gaza.
Batis, the commander of the fortress of Gaza, refused to surrender to Alexander. Though a eunuch, Batis was physically imposing and ruthless. After three unsuccessful assaults, the stronghold was finally taken by force, but not before Alexander received a serious shoulder wound. When Gaza was taken, the male population was put to the sword and the women and children were sold into slavery. According to the Roman historian Quintus Curtius Rufus, Batis was killed by Alexander in imitation of Achilles’ treatment of the fallen Hector. A rope was forced through Batis’s ankles, probably between the ankle bone and the Achilles tendon, and Batis was dragged alive by chariot beneath the walls of the city. Alexander, who admired courage in his enemies and might have been inclined to show mercy to the brave Persian general, was infuriated at Batis’s refusal to kneel and by the enemy commander’s haughty silence and contemptuous manner.
With Gaza taken, Alexander marched into Egypt. The Egyptians hated the Persians, in part because Persia considered Egypt as nothing more than a breadbasket. They welcomed Alexander as their king, placed him on the throne of the Pharaohs, giving him the crown of Upper and Lower Egypt, and named him the incarnation of Ra and Osiris. He set in motion plans to build Alexandria, and, though future tax revenues would be channeled to him, he left Egypt under the management of Egyptians, which helped to win him their support.
Source: Wikipedia
