Battle of Magnesia: How Antiochus III's Cavalry Gamble Against Rome Backfired

Key facts

• Antiochus III ruled the Seleucid Empire from 223 to 187 BC and was called 'the Great' for restoring Seleucid power in Asia Minor, seizing Syria from the Ptolemies, and campaigning in central Asia.
• Rome defeated Macedon at Cynoscephalae in 197 BC and withdrew its legions from Greece; in 196 BC Titus Quinctius Flaminius proclaimed the Greeks free at the Isthmian games.
• Antiochus III landed in Greece in late 192 BC with up to 18,000 troops, was defeated at Thermopylae in 191 BC, and withdrew to Asia.
• The combined forces of Rome, Rhodes, and Pergamon defeated the Seleucid fleet at Myonessus in 190 BC.
• The Roman army at Magnesia numbered 30,000-40,000, including 20,000 heavy infantry, about 3,000 Pergamene and Achaian light troops, 3,000 cavalry, and 16 African elephants.
• Antiochus' army at Magnesia totaled 60,000 infantry and 12,000 cavalry, including a 16,000-man Macedonian phalanx, 6,000 cataphracts, and scythed chariots.
• The Battle of Magnesia took place in late 190 BC (some accounts say January 189 BC) near Mount Sipylum; Roman sources claim over 50,000 Seleucids were killed versus fewer than 400 Romans and Greeks.
• The Peace of Apamea in 188 BC ended Seleucid rule north of the Taurus Mountains, and Rhodes and Pergamon divided the lands between them.