Editing Epaminondas (section)

====First Invasion of the Peloponnese (370&nbsp;BC)====
When, in the immediate aftermath of Leuctra, the Thebans had sent a herald to Athens with news of their victory, the messenger was met with stony silence. The Athenians then decided to take advantage of the Spartan discomfiture, holding a conference in Athens, in which the peace terms proposed earlier in 371 BC were ratified by all cities (except [[Elis (city)|Elis]]); and this time, the treaty explicitly made the Peloponnesian cities, formerly under Spartan dominance, independent.{{sfn|Tritle|1997|p=24}} Taking advantage of this, the Mantineans decided to unify their settlements into a single city, and to fortify it; a decision which greatly angered Agesilaus. Furthermore, [[Tegea]], supported by Mantinea, instigated the formation of an [[Arcadia (ancient region)|Arcadia]]n alliance. This led to the Spartans declaring war on Mantinea, whereupon the majority of Arcadian cities grouped together to oppose the Spartans (thus forming the confederation that the Spartans were trying to prevent), and requested assistance from the Thebans. The Theban force arrived late in 370&nbsp;BC, and it was led by Epaminondas and Pelopidas, both at this time Boeotarchs.{{sfn|Roy|2000|pp=189{{ndash}}190}}{{sfn|Tritle|1997|p=24}} As they journeyed into Arcadia, the Thebans were joined by armed contingents from many of Sparta's former allies, swelling their forces to some 50–70,000 men.{{sfn|Stylianou|1998|p=428}} In Arcadia Epaminondas encouraged the Arcadians to form their proposed league, and to build the new city of [[Megalopolis, Greece|Megalopolis]] (as a center of power opposed to Sparta).{{sfn|Ober|1985|p=41}}

[[File:Messenia.jpg|thumb|[[Messenia]] in the classical period]]
Epaminondas, supported by Pelopidas and the Arcadians, then persuaded the other Boeotarchs to invade Laconia. Moving south, they crossed the [[Evrotas River]], the frontier of Sparta, which no hostile army had breached in memory. The Spartans, unwilling to engage the massive army in battle, simply defended their city, which the Thebans did not attempt to capture. The Thebans and their allies ravaged Laconia, down to the port of [[Gythium]], freeing some of the Lacedaemonian [[perioeci]] from their allegiance to Sparta.{{sfn|Ober|1985|p=41}} Epaminondas briefly returned to Arcadia, before marching south again, this time to [[Messenia]], a region which the Spartans had conquered some 200 years before. Epaminondas freed the helots of Messenia, and rebuilt the ancient city of [[Messene]] on Mount [[Ithome]], with fortifications that were among the strongest in Greece. He then issued a call to Messenian exiles all over Greece to return and rebuild their homeland.{{sfn|Luraghi|2008|p=4}}{{sfn|Ober|1985|p=41}} The loss of Messenia was particularly damaging to the Spartans, since the territory comprised one-third of Sparta's territory and contained half of their [[helots|helot]] population. It had been the helots' labor which had allowed the Spartans to become a "full-time" army.{{sfn|Holland|2006|p=120}}{{sfn|Ober|1985|p=41}}

Epaminondas' campaign of 370/369 BC has been described as an example of "the grand strategy of indirect approach", which was aimed at severing "the economic roots of her [Sparta's] military supremacy."{{sfn|Liddell Hart|1954|p=35}} In mere months, Epaminondas had created two new enemy states that opposed Sparta, shaken the foundations of Sparta's economy, and all but devastated Sparta's prestige.  This accomplished, he led his army back home, victorious.{{better|date=January 2022}}