In order to avoid the prophecy, Laius orders a shepherd to take Oedipus and abandons him to...
Many years prior to the events portrayed in Sophocles's Oedipus Rex, the Oracle foretells that Oedipus would kill his father, Laius, King of Thebes, and marry his mother, Queen Jocasta.
In order to avoid the prophecy, Laius orders a shepherd to take Oedipus and abandons him to die on a mountainside. The shepherd takes pity on the child and gives him to another shepherd, who takes Oedipus to Corinth, where he is adopted by King Polybus and Queen Merope and brought up as their son.
When Oedipus is a young man, a drunken partygoer shouts to him, "Thou art not the true son of thy sire!" When Oedipus askes Polybus and Merope about it, they don't give him a straight answer, so Oedipus goes to the Oracle at Delphi.
OEDIPUS: So privily without their leave I went
To Delphi, and Apollo sent me back
Baulked of the knowledge that I came to seek.
But other grievous things he prophesied,
Woes, lamentations, mourning, portents dire;
To wit I should defile my mother's bed
And raise up seed too loathsome to behold,
And slay the father from whose loins I sprang.
Thinking that Polybus and Merope are his real parents, Oedipus leaves Corinth to avoid fulfilling the prophecy and gos to Thebes. On the way to Thebes, he unknowingly kills King Laius, his real father.
When Oedipus gets to Thebes, he solves the riddle of the Sphynx, relieving the Theban people of a plague, and is made King of Thebes. He is rewarded with marriage to Laius's wife—Jocasta. So Oedipus does, indeed, kill his father and marry his mother.
Oedipus and Jocasta have four children—two girls, Antigone and Ismene, and two boys, Eteocles and Polyneices. Although the children aren't quite so "loathsome" as the Oracle would have Oedipus believe they would be, life isn't much better for Antigone, Ismene, Eteocles, and Polyneices than it is for Oedipus.
In Greek mythology, and in Sophocles's Antigone, Eteocles and Polyneices kill each other in battle during a civil war in Thebes. Antigone is sentenced to death by her uncle, Creon (Oedipus' brother), for burying Polyneices against his direct order, and she is entombed alive until she dies.
Although Ismene has nothing to do with Antigone burying Polyneices and actually warns her against it, she begs Creon to give her the same punishment as her sister. Although Ismene is led out of Creon's palace with Antigone, we later learn about Antigone's death, but we learn nothing at all about Ismene's fate.