Thus arrayed, the army of Thebes marched to meet its foe, in the valley between the two declivities on which the hostile camps were placed. The cavalry met first, and the Theban horsemen soon put the Spartan troop to flight. Then the footmen came together with a terrible shock. Pelopidas and his Sacred Band, and behind them the weight of the fifty shields, proved more than the Spartans, with all their courage and discipline, could endure. Both sides fought bravely, hand to hand; but soon Cleombrotus fell, mortally hurt, and was with difficulty carried off alive. Around him fell others of the Spartan leaders. The resistance was obstinate, the slaughter terrible; but at last the Spartan right wing, overborne by the heavy Theban mass and utterly beaten, was driven back to its camp on the hill-side above. Meanwhile the left wing, made up of allies, did little fighting, and quickly followed the Spartans back to the camp.
It was a crushing defeat. Of seven hundred Spartans who had marched in confidence from the camp, only three hundred returned thither in dismay. A thousand and more Lacedæmonians besides were left dead upon the field. Not since the day of Thermopylæ had Sparta lost a king in battle. The loss of the Theban army was not more than three hundred men. Only twenty days had elapsed since Epaminondas left Sparta, spurned by the scorn of one of her kings; and now he stood victor over Sparta at Leuctra, with her second king dead in his camp of refuge. It is not surprising that to Greece, which had felt sure of the speedy overthrow of Thebes, these tidings came like a thunderbolt. Sparta on land had been thought irresistible. But here on equal ground, and with nearly double force, she had been beaten by insignificant Thebes.
We must hasten to the end of this campaign. Sparta, wrought to desperation by her defeat, sent all the men she could spare in reinforcement. Thebes, too, sought allies, and found a powerful one in Jason of Pheræ, a city of Thessaly. The Theban leaders, flushed with victory, were eager to attack the enemy in his camp, but Jason gave them wiser advice.
"Be content," he said, "with the great victory you have gained. Do not risk its loss by attacking the Lacedæmonians driven to despair in their camp. You yourselves were in despair a few days ago. Remember that the gods take pleasure in bringing about sudden changes of fortune."
This advice taken, Jason offered the enemy the opportunity to retreat in safety from their dangerous position. This they gladly accepted, and marched in haste away. On their journey home they met a second army coming to their relief. This was no longer needed, and the whole baffled force returned home.
The military prestige held by Sparta met with a serious blow from this signal defeat. The prestige of Thebes suddenly rose into supremacy, and her control of Bœotia became complete. But the humiliation of Sparta was not yet near its end. Epaminondas was not the man to do things by halves. In November of 370 B.C. he marched an army into Arcadia (a country adjoining Laconia on the north), probably the largest hostile force that had ever been seen in the Peloponnesus. With its Arcadian and other allies it amounted to forty thousand, or, as some say, to seventy thousand, men, and among these the Thebans formed a body of splendidly drilled and disciplined troops, not surpassed by those of Sparta herself. The enthusiasm arising from victory, the ardor of Pelopidas, and the military genius of Epaminondas had made a wonderful change in the hoplites of Thebes in a year's time.
And now a new event in the history of the Spartan commonwealth was seen. For centuries the Spartans had done their fighting abroad, marching at will through all parts of Greece. They were now obliged to fight on their own soil, in defence of their own hearths and homes. Dividing his army into four portions, Epaminondas marched into rock-bounded Laconia by four passes.
The Arcadians had often felt the hard hand of their warlike neighbors. Only a snort time before one of their principal cities, Mantinea, had been robbed of its walls and converted into open villages. Since the battle of Leuctra the villagers had rebuilt their walls and defied a Spartan army. Now the Arcadians proved even more daring than the Thebans. They met a Spartan force and annihilated it.
Into the country of Laconia pushed the invaders. The city of Sellasia was taken and burned. The river Eurotas was forded. Sparta lay before Epaminondas and his men.