The Shield of Heracles (also known as The Shield of Herakles, Aspis Herakleous) is a poem of 480 hexameter lines written by an unknown Greek poet in the style of Hesiod (lived 8th century BCE). It deals with the Greek hero Herakles (also known as Hercules) and his nephew Iolaus and their battle with Cycnus, son of the war-god Ares. It is unclear when the action of the poem takes place in the story of Heracles' life in myth and legend, but in the story Heracles and Iolaus are on their way to the city of Trachis (where Heracles and his second wife Deinara lived toward the end of their lives, but no mention is made of her or of any other events in the hero's life besides his birth) when they meet Cycnus and Ares.
The poem was thought to be an original work by Hesiod but was already suspect as the work of another by around the 3rd century BCE. Some modern-day sources continue to attribute the work to Hesiod even though by now it has long been established as the work of another writing in Hesiod's style. The poem borrows heavily from Homer's Iliad, chapter 18, in which he describes the shield of Achilles. The author of The Shield of Heracles took some lines directly from Iliad and only modified others, but the majority of the poem is an original work. It was very popular in Greece, particularly Athens, in the 6th and 5th centuries BCE, and the story inspired representations in art on vases and drinking vessels.
Cyncus was a cruel despot of Thessaly who invited guests to dinner and then murder them. He also would rob those pilgrims who were enroute to the sanctuary of the god Apollo to make sacrifices and leave gifts and offerings. One day, as Heracles and Iolaus were traveling in their chariot through the country, they met Cycnus and Ares in their own chariot coming from the other direction. They both stopped near the sanctuary of Apollo, where Cycnus challenged Heracles to single combat. Apollo, abiding close by in his sanctuary, stirred Heracles' blood to accept the challenge (even though, considering Heracles' temper and general character in the myths, he would have needed no encouragement). Heracles fights Cycnus and kills him with a spear through the throat. Ares then attempts to kill Heracles in revenge but is thwarted by the goddess Athena. Heracles wounds Ares in the thigh in this altercation and beats him. At this point, Ares' other sons, Panic and Dread, appear and take the wounded god back to Mount Olympus to be cared for. Cyncus is buried by King Ceyx of Thessal, and a great monument is set up to honor him, but Apollo causes the river Anaurus to flood and wash the grave away, so that Cycnus' memory would be blotted out because of his many evil deeds.
The poem begins with a description of Heracles' beautiful mother Alcmene and how she was impregnated by both the god Zeus and her husband Amphitryon on the same night, giving birth to twin sons: Heracles (son of Zeus) and Iphicles (son of Amphitryon). Amphitryon killed Alcmene's father, Electryon, over some cattle and then had to make amends before he could sleep with her. He is off at war defeating the kingdom's enemies when Zeus, in the form of Amphitryon, comes to Alcmene; the real Amphitryon returns later to Alcmene's bed after battle. This establishes Heracles as the son of the king of the gods and Iphicles as completely mortal. Iphicles never appears in the poem, but Iolaus, his son, is Heracles' charioteer (lines 1-56).
After setting up the heroes of the tale, the poem presents the challenge to battle between Cycnus and Heracles near Apollo's sanctuary (lines 57-77). Heracles and Iolaus then have a conversation about their lives, the family's history, and the combat which Heracles is confident of winning (lines 78-121). The piece then describes Herakles putting on his armor and preparing for battle (lines 122-138) and goes into a detailed description of the shield which makes up most of the poem (lines 139-317). The shield is a masterwork of Hephaestus, god of the forge, who was directed in the making of it by Zeus himself. It is made of shining gold, adorned with ivory and electrum, and intricately detailed with many figures. The shield has never been broken or crushed - indeed, it cannot be - and features a personification of Fear and another of Strife prominently amidst the other figures of such things as writhing snakes, warriors, and gods such as Zeus and Ares.
Once the description of the shield is completed, the poem follows the heroes as they approach the place of battle (lines 318-326), at which point Athena appears and warns them, when they have killed Cycnus, not to become distracted by stripping the corpse of his armor or taking his horses but to pay attention to Ares who will attack them. She tells Heracles to watch for an opening beneath Ares' shield and to thrust at that spot with his spear to wound the god (lines 327-337). There then follows a description of the combat between Heracles and Cycnus with Iolaus and Ares watching from their respective chariots. The two warriors fight until Heracles drives his spear into Cycnus' throat and kills him (lines 338-423).
Heracles remembers the words of Athena and ignores the prize of Cycnus' shining armor, keeping his eyes on Ares and bracing for his attack. Ares springs upon Heracles, whose great shield withstands the onslaught of the god of war, and the two fight. Ares hurls his war spear, but Athena, watching over the combat, blunts the force of the weapon and causes it to turn aside. She tells Ares that it is not fated that he should kill Heracles and that he should stop fighting now, but Ares is too enraged over the death of his son. He draws his sword and again attacks Heracles who, seeing the moment Athena foretold, stabs Ares in the thigh underneath his shield and drives him to the ground and defeats him. Ares' other sons Panic and Dread then appear in a chariot and rescue their father, carrying him off to Mount Olympus (lines 424-466). The poem concludes (lines 467-480) with Heracles and Iolaus stripping Cycnus of his armor and continuing on their journey to the city of Trachis and descriptions of Cycnus' burial and Apollo bringing the flood to blot out all memory of Cycnus and his cruel works.