What were the Macedonian Seleucid Empire's achievements in military technology and tactics?

The Macedonian Seleucid Empire was a Hellenistic state that existed from 312 BC to 63 BC, and during its time, it made several significant achievements in military technology and tactics. One of its most notable achievements was the development of the sarissa, a long spear that measured up to 18 feet in length. This spear was wielded by the phalanx, a formation that consisted of soldiers standing shoulder to shoulder with the sarissa in hand. The phalanx was a powerful formation that allowed for rapid movement, and it was instrumental in the empire's military successes.

In addition to the sarissa, the Macedonian Seleucid Empire also made advancements in siege warfare, developing sophisticated catapults and siege engines. The empire also employed innovative tactics, such as the use of war elephants on the battlefield. The Seleucid military was also known for its use of mercenaries, drawing soldiers from a variety of ethnic groups and nationalities to bolster its armies.