Inspired by the Greek legend, Oedipus Rex, by Sophocles, Freud's discovery of the Oedipus Complex was made during his self-analysis (more info on the myth in Answers.com)

The Oedipus Complex (3-5 years of age) is a characteristic constellation of loving and hostile wishes that children experience towards their parents at the height of the phallic phase.

In its positive form, the rival is the parent of the same sex and the child desires a sexual union with the parent of the opposite sex.

In its negative form, the rival is the parent of the opposite sex while the parent of the same sex is the loved one.

In its complete form, at the unconscious level, both positive and negative forms coexist due to the child's ambivalence and need for protection. The dialectical relation to each other will determine whether human desire will follow a heterosexual or homosexual orientation.

In this triangular structure the interaction between the parents' unconscious desires and the child's instincts play an essential role in the constitution of the Oedipal scenario.

The prohibition against incest is a universal law in the most varied cultures. Hamlet's destiny shows that even a disguised Oedipal triumph may be a haunting shadow despite the tragic "gratification" of his unconscious desire.

In "The Dissolution of the Oedipus Complex" (1924d) Freud says:"If the ego has in fact not achieved much more than a repression of the complex, the latter persists in an unconscious state in the id and will later manifest its pathogenic effect" [SE, XIX, 177]

The decline of the Oedipus Complex and the entry into the latency period are related to threat of castration (boys) and the desire for a baby (girls). The resolution of the complex after puberty is possible through the choice of a suitable substitute for the object of love.

The Oedipus Complex keeps its function of an unconscious organizer throughout life and forms an idissoluble link between wish and law.