The Battle of Gaza was a battle of the Third war of the Diadochi between Ptolemy (satrap of Egypt, later known as Ptolemy I Soter) and Demetrius (son of Antigonus I Monophthalmus).

Ptolemy decided an invasion of Syria. With 18,000 infantry and 4,000 cavalry he arrived to Gaza in early 312 BC. Demetrius decided to offer him battle.

Demetrius:

left wing: 2,900 cavalry, 1,500 light infantry and 30 war elephants under Demetrius command
center: 11,000 infantry phalanx and 13 elephants
right wing: 1,500 cavalry

Ptolemy:

left wing: 3,000 cavalry
center: 18,000 phalanx
right wing: 1,000 cavalry