The immediate outcome of Cynoscephalae is favorable for Thebes and Thessaly is reorganized in a way that gives Thebes for the first time an absolute majority of votes on the Delphic Amphictyony, but active Theban interference in Thessaly is over.

Epaminondas in 364-363 BCE makes a bold attempt in 364-363 BCE to challenge Athens' naval empire.

Some naval interest on the part of Thebes can perhaps already be inferred from its designs on Thessaly, with its good harbors.

Theban rivalry with Athens had become explicit  after 365 BCE, however; Thebes plans a fleet of one hundred triremes, …

…lures away Athenian allies such as Rhodes and Byzantium, and …

…induces a revolt on Ceos.

This scheme is no more successful than the Thessalian entanglement: Athens will reduce the island in 362 and establish a monopoly of ruddle (red-earth dye), the island's principal product.

The Boeotian League intervenes also in the Arcadian federation in the Peloponnese, which has split in two; the Tegean party appeals for help to the Thebans (who in turn have for allies the Argives and Messenians), and …

…the Mantineans to Athens and Sparta.

The outbreak of civil war in the Arcadian league in 362 brings Epaminondas once more to the head of a large allied army in the Peloponnese.

Leading the Boeotians and their Argive allies against Sparta, Athens, and their allies in an encounter on the Mantineian Plain, Epaminondas repeats on a large scale the tactics of Leuctra, cleverly outmaneuvering the Spartan troops, and is once more victorious but dies of a wound on the field of battle.

The great Battle of Mantinea (“Second Mantinea,” to distinguish it from the events of 418) is a technical victory for Thebes in the strictly military sense, but (as Xenophon notes) it is actually indecisive: Epaminondas' death permanently crushes Theban hopes of leadership in Greece.

The peace after the battle in effect recognizes the independence of the Messenians, thus settling at the diplomatic level an issue that in reality has been settled for years.

All constructive initiative appears to vanish with the death of Epaminondas from the policy of Thebes, which begins a rapid decline from its decade-long position as Greece's preeminent city-state.

Agesilaus attempts to increase Sparta's revenues by leading Spartan mercenaries in Anatolia and in Egypt, but the city-state fails to recover the military preeminence lost at the Battle of Leuctra.

Agesilaus, Eurypontid king of Sparta, had twice rescued Sparta from attacks by the Theban leader Epaminondas but had taken no part in the subsequent Battle of Mantineia.

Agesilaus, commanding a body of Greek mercenaries in 361, is abroad serving Tachos, or Teos (also known as Zedhor), second king of the native Thirtieth Dynasty of Egypt.

Tachos, however, insists on leading the Egyptian army himself, and Agesilaus, after quarreling with his ally, supports a military revolt in Egypt that places the young pretender Nectanebo II on the throne.

A rival pretender almost succeeds in overthrowing the new king, but Agesilaus defeats him and leaves Nectanebo firmly established as ruler. (Tachos flees to the protection of Artaxerxes II in Persia, where he will die an exile.)

The death of Epaminondas in 362 BCE has freed Athens from fear of Thebes, but it appears at the same time to have exposed it to further aggression from Alexander of Pherae, who makes a piratical raid on Tinos and other cities of the Cyclades, plundering them, and enslaving the inhabitants.