Battle of Leuctra

In the summer of 371 BC, usually dated to 6 July, a Boeotian army under the Theban general Epaminondas defeated a larger Spartan-led force near the village of Leuctra in Boeotia, central Greece. The Spartan king Cleombrotus I was killed, and the defeat broke the dominance Sparta had enjoyed since winning the Peloponnesian War. For about a decade afterwards Thebes was the leading power in Greece.

The King's Peace of 387/6 BC, which ended the Corinthian War, guaranteed the autonomy of Greek cities outside Persian control. Sparta, acting as its enforcer, used that clause to break up the Boeotian League led by Thebes, and in 382 BC a Spartan force seized the Theban citadel, the Cadmea. Theban exiles overthrew the pro-Spartan regime in late 379 BC and began rebuilding the league, leading to years of war with Sparta.

In 371 BC the Greek states met to agree a new general peace. The Theban envoys wanted to sign for all of Boeotia; the Spartans insisted that each Boeotian city sign separately. Thebes refused and found itself isolated, and Cleombrotus marched his army from Phocis into Boeotia by an unexpected southern route, meeting the Boeotians at Leuctra.

The ancient sources disagree on numbers, and later writers give implausibly large Spartan totals. Modern historians generally estimate about 10,000 infantry and 1,000 cavalry on the Spartan side, including some 700 full Spartan citizens, against roughly 7,000 Boeotian infantry and 700 cavalry. Pelopidas commanded the Sacred Band, an elite Theban unit of 300.

Greek armies normally fought in an even phalanx, perhaps eight ranks deep, with the best troops on the right. Epaminondas broke with this. He stacked his Thebans on the left, according to Xenophon at least fifty shields deep, directly facing the Spartans and their king, while holding back his weaker Boeotian allies in a staggered line to the right. The idea was to win the battle by crushing the Spartan wing alone.

Four ancient writers describe the battle, and their accounts conflict. Xenophon, the only contemporary, says the Spartan cavalry was beaten early and fled back through its own infantry, disordering it just as the Thebans charged. Plutarch says Pelopidas and the Sacred Band struck while the Spartans were shifting their formation. Either way, the deep Theban column drove into the Spartan right. Cleombrotus was mortally wounded, the Spartan wing gave way, and the allied left wing then retreated as well.

According to Xenophon, the Spartan side lost nearly 1,000 dead, about 400 of them Spartiates. The Boeotian losses were light: about 300 according to Diodorus, and only 47 according to Pausanias. Both sides then called for reinforcements, but Jason of Pherae, Thebes' ally, persuaded the Thebans to let the Spartans withdraw under truce.

Sparta lost more than a quarter of its full citizens, and its reputation for invincibility was gone. In the winter of 370/69 BC a Theban-led army invaded Laconia and Messenia, the first land invasion of the Spartan homeland on record, and freed Messenia and its helots. Within a decade Sparta had lost its alliance and half its territory. Theban leadership proved short-lived, however, ending with the death of Epaminondas at the Second Battle of Mantinea in 362 BC.

The tactics used at Leuctra, concentrating force at one point while holding back the rest of the line, influenced Philip II of Macedon, who lived in Thebes as a hostage in the 360s BC. Philip and his son Alexander used similar methods in victories such as the Battle of Chaeronea and in the Wars of Alexander the Great. Some historians argue that Epaminondas's oblique line was less a planned innovation than an improvised answer to being outnumbered.

The battle falls between our 400 and 323 BCE maps. Leuctra lies in central Greece, and the 323 BCE map shows how the Greek world had passed under Macedonian power within a generation.