The Battle of Magnesia was a decisive military engagement that occurred in either December 190 or January 189 BC. It served as a pivotal conflict during the Roman–Seleucid War, pitting the forces of the Roman Republic against the Seleucid Empire.
The Roman army, led by the consul Lucius Cornelius Scipio Asiaticus and supported by the Kingdom of Pergamon under Eumenes II, confronted the Seleucid forces commanded by Antiochus III the Great. The armies spent several days maneuvering near Magnesia ad Sipylum, attempting to secure advantageous terrain before the final confrontation.