The Battle of Idomene was a battle in the Peloponnesian War

Peloponnesian War

The Peloponnesian War, 431 to 404 BC, was an ancient Greek war fought by Athens and its empire against the Peloponnesian League led by Sparta. Historians have traditionally divided the war into three phases...

 in 426 BC

426 BC

Year 426 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Tribunate of Cincinnatus, Albinus, Fusus and Cossus...

, between the Athenians

Athens

Athens , is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state...

 and the Ambracia

Ambracia

Ambracia, occasionally Ampracia , was an ancient Corinthian colony, situated about 7 miles from the Ambracian Gulf in Greece, on a bend of the navigable river Arachthos , in the midst of a fertile wooded plain.-History:...

ns.

The Ambracians, who were allies of the Spartans

History of Sparta

The History of Sparta describes the destiny of the ancient Dorian Greek state known as Sparta from its beginning in the legendary period to its forced incorporation into the Achaean League under the late Roman Republic, its conquerors, in 146 BCE, a period of roughly 1000 years...

, had sent a relief force to help the army that had invaded Amphilochia previously. Unbeknownst to the Ambracians, the first army had been defeated, surrounded and scattered by the allied Athenians, Amphilochians and Acarnania

Acarnania

Acarnania is a region of west-central Greece that lies along the Ionian Sea, west of Aetolia, with the Achelous River for a boundary, and north of the gulf of Calydon, which is the entrance to the Gulf of Corinth. Today it forms the western part of the prefecture of Aetolia-Acarnania. The capital...

ns the day before. The Ambracians, unaware of the incoming Athenian army, camped on the lower of two steep hills. Demosthenes

Demosthenes

Demosthenes was a prominent Greek statesman and orator of ancient Athens. His orations constitute a significant expression of contemporary Athenian intellectual prowess and provide an insight into the politics and culture of ancient Greece during the 4th century BC. Demosthenes learned rhetoric by...

, the Athenian commander, occupied the higher hill, obtaining a strategic advantage. Before dawn, while the Ambracians were still asleep, they were attacked and destroyed by the Athenians.

Overall, the Ambraciots lost about 1,000 men over the two battles. Thucydides

Thucydides

Thucydides was a Greek historian and author from Alimos. His History of the Peloponnesian War recounts the 5th century BC war between Sparta and Athens to the year 411 BC...

describes this disaster as: 'The greatest disaster to strike a single city in an equal number of days in this war.'