Ephesus serves in 396 BCE as the headquarters of Agesilaus, who directs from Anatolia Sparta's campaign against the Persians, who in 397 BCE had begun to build a new fleet to deal with the menace of a Spartan army in Asia. (It may be a further irritant that Sparta is helping another anti-Persian rebel in Egypt; this threatens a serious economic loss to the Persian landowners who have been exploiting it at a distance.)

Agesilaus makes a three months' truce with the Persians; during this interim, he manages to shake off Lysander's control over him.

Agesilaus then raids Phrygia and …

…Lydia.

The Boeotian city of Orchomenus by the beginning of the fourth century BCE is pursuing an anti-Theban policy.

Thebes has exercised control over Boeotia in an unrecognized but progressively real way since 446 BCE.

One source of Theban strength is the takeover in 427 BCE of Plataea's vote and some of its territory; another lies in the depredations that the Thebans had been able to carry out in Attica as a result of the occupation of Decelea.

Sparta reinforces its position at Heraclea in Trachis in the early 390s and …

…maintains a garrison at Thessalian Pharsalus.

Initially, Lysander seems to have been at the back of this northward encroachment (good evidence connects him with Thrace and the Chalcidice).

Because Sparta has always expanded in this direction if given the chance, it had not pulled out of central Greece during Lysander's temporary eclipse after 403 BCE.

From the point of view of Thebes and Corinth, there is a risk of encirclement by Sparta.

The expedition of Dercyllidas (399 BCE -397 BCE) had followed that of Thibron in support of the Anatolian Greeks, but the new Spartan king, Agesilaus, leads the most ambitious of all.

When Agesilaus prepares to leave for Anatolia, …

…he tries to sacrifice at Aulis “like Agamemnon” before the Trojan War; but the Boeotian federal magistrates stop him.

Although they have little to fear from a Spartan presence in Anatolia, hardly a normal object of Theban ambition, Theban alarm can be explained by developments nearer home.

Sparta's interference in Corinth's colony, Syracuse, may be another factor making for specifically Corinthian resentment.

Corinth, unlike Thebes, has emerged badly from the Peloponnesian War; its prosperous middle class has been eroded, and this makes possible a remarkable turn of events: Corinth and …

The siege of Syracuse had met with great success throughout 397 BCE, but in 396 BCE, plague again ravages the Carthaginian forces.

This plague, bearing similarities with the Athenian plague, may have been caused by bad hygienic practices on marshy grounds, and malaria may have played a part also.

The result is that scores of soldiers and sailors succumb to the disease, burial parties are overwhelmed, bodies are hastily buried, new burials are almost impossible, and the stench of decaying bodies hangs in the air.

Fear of infection may have prevented proper care being given to the sick.

The cause of this calamity is attributed to the desecration of Greek temples and tombs.

At the Siege of Akragas (406 BCE) Himilco had dealt with a similar situation by sacrificing a child and various animals to appease this alleged divine anger.

Whatever measures (if any) Himilco takes at Syracuse to combat the plague prove ineffective; Punic forces are decimated and the fleet readiness is diminished.

Himilco and the Carthaginians stubbornly stand their ground and remain in the camp, but the morale of the Carthaginians plummets as a result of the plague, along with the combat effectiveness of their forces.