Answer
Three years after losing the decisive Battle of Magnesia in 190 BC against the Roman forces led by Lucius Cornelius Scipio Asiaticus, Antiochus III, the Seleucid ruler, met his demise. This conflict marked a significant turning point, diminishing the Seleucid Empire's power and influence. Antiochus III's untimely death brought an end to his ambitions of restoring his kingdom's former glory.