The Battle of Magnesia was the decisive battle of the Roman-Seleucid War, fought in 190 BC. The allied armies of Rome and Pergamon decisively defeated the Seleucid ruler Antiochus III the Great on the Anatolian coast, forcing Antiochus to make peace two years later and grant large territorial concessions to Pergamon and Rodos.
Background[]
In 190 BC, the Roman general Lucius Cornelius Scipio crossed through Macedonia and Thrace and into Asia Minor with an army of 40,000 troops, including Greek allies from Pergamon. Antiochus III the Great tried to negotiate, but Roman demands were too high, so he had no other choice but to fight the Romans at Magnesia on the Anatolia coast in December of that year. Antiochus had more than 70,000 troops, including 12,000 cavalry and 54 elephants, while the Romans had 40,000 troops.
Battle[]
The Seleucid army was positioned between two rivers, while the Romans deployed infantry on their center and left and a few cavalry squadrons on their extreme left. The Roman infantry consisted of legionaries and Italic allies, and they deployed young hastati in the front, experienced principes behind them, and veteran triarii as the final rank. The right flank was manned by Greek peltasts and heavy cavalry, while they kept 16 elephants in reserve. The Seleucid center was built around ten phalanxes and two units of Galatian allies, with elephants between each of these groups. Each flank had 4,000 heavy cavalry (including cataphracts), with 16 elephants between each group of cavalry. Both armies positioned light missile troops in front of their cavalry. The battle began when the Seleucid chariots attacked the Roman right flank. This attack was greeted by a hail of slings, arrows, and pila, and the Seleucid chariots made a panicked retreat. Roman cavalry and heavy peltasts then attacked the cataphracts, who were killed to the last man. However, the Roman left was attacked by Antiochus himself, leading cavalry and light infantry. The Roman legion defending the left had to retreat back to the camp, where they reformed their lines with help from their Macedonian allies. The legionaries then held their position and stopped Antiochus' attack. Unfortunately for the phalanx, it had lost cavalry support on both flanks and was encircled. The disciplined phalangists tried to retreat to the camp, but they were attacked by infantry, cavalry, and missile units, and Antiochus failed to relieve his center in time, as the Romans were already attacking his camp. Antiochus fled to Sardis, having lost most of his army. In 188 BC, peace was made at Apamea.