Upon arriving, Alexander camped near the southern side of the city and deemed the southern walls as the weakest. Near these weak points, Alexander built the mounds that were eventually used to enter the city. It is alleged the mounds were built quickly, despite the engineers' belief they could not be completed due to the nature of Gaza's fortifications.
One day during the siege, the Gazans made a sortie against enemy siege equipment constructed on site, and Alexander led his shield bearing guards into counterattack. Alexander's shoulder was injured in the attempt. According to Arrian, the rest of the mound was completed shortly after, around the whole of Gaza. At some undefined period after this, the siege equipment from Tyre arrived, and was put into use also. It was after this that major sections of the wall were broken by the Macedonians. After three attempts to enter the city, the Macedonians finally entered the city. The Gazans fought bitterly.
Batis refused to surrender to Alexander. 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.
As a result of the Siege, Alexander was allowed to proceed south into Egypt securely, without his line of communications being threatened from the North by Batis from Gaza.