What is the Theban Saga?

The Theban Saga is a collection of sagas, or legends, that focuses on important events in mythology around the founding of Thebes, a major city in Boeotia which is a region in mainland Greece. It also contains stories about the different kings of Thebes and their families.
The first myth of the Theban Saga tells of the founding of Thebes. Thebes was founded soon after Zeus took the form of a bull and kidnapped Europa, taking her to Crete. There, she gave birth to Minos, whose father was Zeus, and Minos eventually became the first king of Crete. Cadmus, Europa's brother, went to look for her in Greece, and he was instructed by the oracle at Delphi to found a city. In Boeotia, he founded Cadmeia, which was later known as Thebes.
The Theban Saga continues with tales about the descendants of King Cadmus of Thebes. One story talks of King Laius, who was famously murdered by his son, Oedipus, as predicted by the oracle at Delphi. Oedipus did not knowingly kill his father. However, he encountered an old man on the road, and Oedipus killed him in anger after the old man's chariot struck his chariot. Later, when Oedipus marries his mother Jocasta (also without realizing her real identity and also in accordance to the prediction of the oracle), Oedipus becomes king of Thebes. He became the king of Thebes after successfully answering one of the Sphinx's riddles.
Antigone, the daughter and sister of Oedipus, is the subject of Sophocles's tragedy of the same name. Tiresias, the blind prophet from The Odyssey, also plays a role in the Theban legends of Oedipus and Antigone.