Birth of Aegisthus: Thyestes and Pelopia
Catalogue ID: 03-heroes/115-aegisthus-birth-thyestes-pelopia
Cycle: Heroes — Tantalid / Mycenaean; prelude to Agamemnon’s murder
Version line: Apollodorean / Hyginus (oracle; night rape; sword-token; recognition)
Sources: Apollodorus, *Epitome* 2.14; Hyginus, *Fabulae* 87–88; Aeschylus, *Agamemnon* (Aegisthus as adult avenger—birth not narrated); Sophocles / Euripides (Aegisthus as Clytemnestra’s partner)
Source file: /workspace/greek-myth-catalogue/03-heroes/115-aegisthus-birth-thyestes-pelopia.md
Characters
- Aegisthus — son of Thyestes and Pelopia; goat-nursed; killer of Atreus; later of Agamemnon
- Agamemnon — later victims/partners in the nostos crime (aftermath)
- Atreus — husband of Pelopia; foster-father of Aegisthus; slain by him
- Goat — nurse of the exposed infant (etymological aition)
- Oracle — commands the incestuous begetting as price of revenge
- Pelopia — daughter of Thyestes; raped; mother of Aegisthus; wife of Atreus; suicide
- Thyestes — father and (by oracle) incestuous begetter; later co-ruler restored
Places
- Atreus’s flocks — exposure and goat-nursing of the infant
- Mycenae — Atreus’s house; Aegisthus’s rearing; murder of Atreus
- Sicyon — night of Pelopia’s rape
Themes
Narrative
After the banquet, an oracle told Thyestes that he would be avenged on Atreus only by a son born of his own daughter. Thyestes, unknowing or half-knowing, came by night to Sicyon (or a Pelopid court) where his daughter Pelopia served. He raped her in darkness; she stole his sword as a token. Pelopia later married Atreus (who thought her another’s daughter); she bore Aegisthus and exposed him, or gave him to shepherds; a goat (*aix*) suckled him—folk etymology of Aegisthus.
Atreus reared the boy as his own and, when Aegisthus was grown, sent him to kill Thyestes. At the recognition the sword (or Pelopia’s confession) revealed the truth: Aegisthus was Thyestes’ son by incest. Pelopia killed herself with the same sword; Aegisthus gave it to Thyestes and, with his father, killed Atreus and seized Mycenae. Thus the oracle’s monstrous child becomes the partner of Clytemnestra and the murderer (with her) of Agamemnon—Thyestes’ revenge delayed into the next war’s homecoming. The birth story closes the feud’s generation of crimes: adultery, stolen lamb, cannibal feast, and incestuous conception of the final blade.