The Battle of Gaza was a battle of the Third war of the Diadochi between Ptolemy (and Seleucus) against Demetrius (son of Antigonus I Monophthalmus). In late 312 BC, Ptolemy launched an invasion from Egypt, he marched with 18,000 infantry and 4,000 cavalry along the northern edge of the Sinai. Receiving timely intelligence, Demetrius recalled his troops from their winter quarters and concentrated them at Gaza. Demetrius's advisors told him not to fight the more experienced Ptolemy and Seleucus, but he ignored their advice. Armies and deployment Demetrius deployed 2,900 elite cavalry, 1,500 light infantry, and 30 Indian war elephants under his command on the left. The Antigonid phalanx of some 11,000 was deployed in the center, with 13 war elephants in front and light infantry protecting the main line. On the Antigonid right, there were 1,500 cavalry. Ptolemy and Seleucus originally put most of their cavalry on the left, but when they learned of Demetrius' disposition, they massed their 3,000 heavy cavalry to the right, under their personal command. An anti-elephant corps of 3,000 light infantry (peltast, archers and slingers) equipped with anti-elephant devices (spikes connected by chains) were positioned in front of the cavalry, with orders to throw the devices in the path of the elephants and then target the mahouts. Their phalanx was stationed in the center, with the remaining 1,000 cavalry deployed on the right. Battle The battle opened with the advance guards of the stronger cavalry wings engaging each other. Demetrius drove off the enemy. Ptolemy and Seleucus responded by riding around Demetrius's left flank to attack. A fierce melee ensued, with the cavalry of both sides fighting with their swords after their lances had been shattered. While the cavalry battle on the flank was taking place, Demetrius brought forward his elephants apparently hoping to demoralize the Ptolemaic phalanx. As the elephants approached, the Ptolemaic archers and javelinmen began showering the elephants and their crews. This, along with some elephants stepping on the spiked chains, led to them becoming panicked. After shooting down nearly all the crews, the Ptolemaic light infantry were able to capture and kill most of the elephants. The loss of the elephants panicked Demetrius' cavalry and many of his men retreated. The infantry then engaged, and the fight was stiff. However, neither phalanx could gain the upper hand. After trying to keep more cavalry from retreating, Demetrius and the remaining cavalry