Sometime later, Polynices, a banished prince of Thebes, arrived in Argos; he approached Adrastus and pleaded his case to the king, as he requested his aid to restore him to his original homeland.

The expedition proved to be a complete disaster, however, as all seven of the Argive champions were killed in the ensuing battle, except for Adrastus, who escaped thanks to his horse Arion, who was the fastest of all of his brethren.

The main battle took place at Glisas where Prince Aegialeus (son of Adrastus and heir to the throne) was slain by King Laodamas, who was in turn killed by Alcmaeon.

Having achieved their objective, the Epigoni returned home, but not before they installed Thersander, son of the fallen prince Polynices (the instigator of the first Theban expedition), as the city's new ruler.

Diomedes attacked and seized the kingdom, slaying all the traitors except Thersites, Onchestus (who escaped to Peloponnesus) and Agrius (who killed himself) restoring his grandfather to the throne.

Unable to find the murderers, Diomedes founded a mythical city called "Oenoe" at the place where his grandfather was buried to honour his death.

Both of them were favorite heroes of Athena and each shared characteristics of their patron goddess – Odysseus her wisdom and cunning, and Diomedes her courage and skill in battle; though neither was wholly bereft of either aspect.

When he decided to sacrifice his daughter to Artemis, Odysseus carried out this order of Agamemnon by luring Iphigenia from Mycenae to Aulis, where murder, disguised as wedding, awaited her.

Apart from his outstanding fighting abilities and courage, Diomedes is on several crucial occasions shown to possess great wisdom, which is acknowledged and respected by his much older comrades, including Agamemnon and Nestor.

Some scholars claim that this part of the epic was originally a separate, independent poem (describing the feats of Diomedes) that Homer adapted and included in the Iliad.

[17] Diomedes' aristeia represents many of his heroic virtues such as outstanding fighting skills, bravery, divine protection/advice, carefully planned tactics of war, leadership, humility and self-restraint.

He continues to make havoc among the Trojans by killing Astynous, Hypeiron, Abas, Polyidus, Xanthus, Thoon, Echemmon and Chromius (two sons of Priam).

Diomedes then withdraws from combat having failed to kill Aeneas, but succeeding in obtaining what he considers to be the finest steeds alive (and later in Book XXIII, winner of the chariot race for Patroclus, despite starting in last place).

According to the instructions of Helenus, Priam's wife gathered matrons at the temple of Athena in the acropolis and offered the goddess the largest, fairest robe of Troy.

Nestor responded, "Son of Tydeus, though Hector say that you are a coward the Trojans and Dardanians will not believe him, nor yet the wives of the mighty warriors whom you have laid low."

At the end of the day's battle, Hector made one more boast, "Let the women each of them light a great fire in her house, and let watch be safely kept lest the town be entered by surprise while the host is outside...

Finally Hector managed to send Dolon, a good runner, after making a false oath (promising him Achilles' horses after the victory).

In Book XIII, Idomeneus praises Meriones and claims the best warriors do in fact excel in both types of warfare, 'lokhos' (ambush) and 'polemos' (open battle).

Idomeneus' words portray ambush, "the place where the merit of men most shines through, where the coward and the resolute man are revealed", as a type of warfare only for the bravest.

According to another version of the story, it had been foretold by an oracle that if the stallions of Rhesus were ever to drink from the river Scamander, which cuts across the Trojan plain, then the city of Troy would never fall.

Achilles explains that his immortal steed, originally a gift of Poseidon to his father, excels all others, and although would win, his horses are weeping the death of their driver Patroclus rather than racing.

Seeing this, Athena gives the whip back to Diomedes and puts fresh strength into the horses while breaking the yoke of Eumelus, who gets thrown off and injured.

[30] During the sacking and looting of the great city, the seeress Cassandra, daughter of Priam and Hecuba, clung to the statue of Athena, but the Lesser Ajax raped her.

Still others say that despite Diomedes's noble treatment of her son Aeneas, Aphrodite never managed to forget about the Argive spear that had once pierced her flesh in the fields of Troy.

[35] The Greeks and Romans credited Diomedes with the foundation of several Greek settlements in Magna Graeca in southern Italy:[36] Argyrippa or Arpi, Aequum Tuticum (Ariano Irpino), Beneventum (Benevento), Brundusium (Brindisi), Canusium (Canosa), Venafrum (Venafro), Salapia, Spina, Garganum, Sipus (near Santa Maria di Siponto),[37] Histonium (Vasto), and Aphrodisia or Venusia (Venosa).

[40] Ovid, on the other hand, writes that Venulus came to the home of exiled Diomedes in vain, but he was erecting walls with the favour of Iapygian Daunus, his new father-in-law, which would make the city Luceria, not Argyrippa.

There are also vestiges of this cult in areas like Cyprus and some mainland Greek cities, given the inscriptions on votive offerings found in temples and tombs, but the popularity is most evident along the Eastern coast of Italy.

At Argos, his native place, during the festival of Athena, his shield was carried through the streets as a relic, together with the Palladium, and his statue was washed in the river Inachus.

According to a legend, the goddess Venus seeing the men of Diomedes cry so bitterly transformed them into birds (Diomedee) so that they could stand guard at the grave of their king.

Diomedes plays an important role in the medieval legend of Troilus and Cressida, in which he becomes the girl's new lover when she is sent to the Greek camp to join her traitorous father.