1. The Battle of Thermopylae (480 BCE)

The Spartans’ defeat at Thermopylae was a tactical loss but a strategic victory for Greece. Their legendary resistance galvanized the Greek city-states, transforming fragmented rivals into a unified force. This newfound unity paved the way for decisive victories against Persia at Salamis and Plataea. Thermopylae’s ultimate impact wasn’t in its outcome but in its enduring legacy of valor and unity. The loss became a rallying cry for freedom and remains a powerful symbol today.