Aeschylus' Oresteia

A Trilogy: three parts
Earlier versions of the myth
Background to the myth:
Aeschylus used the myth to meditate on the shift from the lawless retributive "justice" of revenge/vendetta/lex talionis/feud to the rule of law.
Aeschylus also explores the notion of responsibility:
Contrast this play and the Persians with what we know of Euripides and the themes he treats.

What of Oedipus? Was he responsible for his actions or not?