The Seleucid army was the army of the Seleucid Empire, one of the numerous Hellenistic states that emerged after the death of Alexander the Great. As with the other major Hellenistic armies, the Seleucid army fought primarily in the Greco-Macedonian style, with its main body being the phalanx. The phalanx was a large, dense formation of men armed with small shields and a long pike called the sarissa. This form of fighting had been developed by the Macedonian army in the reign of Philip II of Macedon and his son Alexander the Great. Alongside the phalanx, the Seleucid armies used a great deal of native and mercenary troops to supplement their Greek forces, which were limited due to the distance from the Seleucid rulers' Macedonian homeland.