A threat before the quest
In the Library, Acrisius learns that his daughter Danae will bear the grandson who kills him. He confines her, yet Perseus is born. The compiler records competing accounts of his conception, including Zeus entering as a stream of gold. Acrisius casts mother and child out to sea in a chest. They reach Seriphos, where Dictys raises the boy.
The next danger is political rather than monstrous. Polydectes, the island’s ruler, desires Danae and wants her grown son out of the way. During a collection of wedding gifts, Perseus boasts that he could provide even a Gorgon’s head. Polydectes turns the boast into a command. The expedition begins in the vulnerability of a mother and son living under another man’s power.
Source: Library and Epitome · Library 2.4.1–2
Seeing without being seen
Athena and Hermes guide Perseus to the Graeae, sisters who share an eye and a tooth. By taking these objects temporarily, he obtains directions to nymphs holding the equipment he needs: winged sandals, a carrying bag, and the cap of Hades that makes its wearer invisible. Hermes also provides a cutting weapon.
Medusa alone among the three Gorgons is mortal. Perseus approaches while the sisters sleep and looks at Medusa’s reflection in a bronze shield rather than directly at her. Athena guides his hand. When he cuts off her head, Pegasus and Chrysaor emerge; the compiler identifies Poseidon as their father. Perseus bags the head and escapes the pursuing sisters under the protection of the cap. His achievement combines divine assistance, calculated coercion, tools, and caution. It is not an unaided test of physical courage.
Source: Library and Epitome · Library 2.4.2
A weapon that outlives its owner
On the return journey, Perseus rescues Andromeda from a sea monster and marries her. Back on Seriphos he finds Danae and Dictys seeking refuge from Polydectes. He displays the head and turns the ruler and his companions to stone. The borrowed equipment returns to its owners, and Athena receives the head for her shield.
The original prophecy nevertheless survives these victories. At athletic games in Larissa, Perseus accidentally strikes Acrisius with a discus. He does not intentionally murder the grandfather who tried to destroy him. The ending separates intention from outcome and shows how a successful rescue story can remain inside a tragic family prediction. This account follows a late compiler; details should not be projected into every earlier image of Perseus. The monster’s decapitation is only one episode in a larger sequence about threatened kinship, borrowed power, and the limits of escape.
Source: Library and Epitome · Library 2.4.3–4
- Period / witness
- Greek mythographic compilation, probably first or second century CE; Frazer translation 1921
- Recording context
- The Library attributed to Apollodorus survives through medieval manuscripts; its lost ending is known through epitomes. This later compilation preserves earlier traditions without dating their beginnings.
A recording location is not necessarily a story’s origin. Dates of texts, copies, and translations answer different questions.
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These references support the explanation above. Rights and edition notes are recorded individually.
Library and Epitome ↗
Pseudo-Apollodorus (ancient author uncertain); translated by Sir James George Frazer · Greek compilation probably first or second century CE; ending survives through later epitomes; Frazer translation 1921; host text page dated 2026-10-05
Edition & rights note