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.