Seleucid Legions

In this Timeline, Antiochus IV Epiphanes of the Seleucid Empire succeeds in reforming the military of the Seleucid army in 168 B.C to resemble the Roman system. Having seen the complications of the phalanx wall - such as its lack of manoeuvrability and flexibility, the entire concept of the sarissa phalanx is replaced, bringing the Seleucid Empire greater military success, both against its old enemies such as the Ptolemaic dynasty and new ones like the Hayasdan and of course, the Roman Republic.

Context and Point of Divergence
In 168 BC, the kingdom of Macedon was defeated at the Battle of Pydna. Though the phalanx was able to keep the Roman infantry at bay initially, as the Roman lines began to retreat, the phalanx had to traverse much rougher terrain. This broke up the phalanx, creating gaps, which the Roman army could exploit, leading them to victory. For the Seleucid Emperor, Antiochus IV, this was a grave worry - his army was quite frankly out of date and vulnerable. He immediately set about modernising the army. Seeing the Roman system of maniples of heavy infantry armed with gladii as the future, the entire corps of the Argyraspidae - 10,000 elite troops chosen from around the empire - was retrained and re-equipped to resemble the Roman Triarii. The phalanx was abandoned, but not the Hetairoi - the "Companions", elite heavy cavalry that proved to be vital time and time again. The standard levied phalangites were replaced by infantry armed with a sword similar to the Gladius Hispaniensis, which could inflict gruesome stabbing wounds in battle.