hey, i found this, it makes what were were chatting about look a little easier to understand about orestes and agamemnon etc: its from:http://www.sparknotes.com/lit/mythology/section11.rhtml

In the newest generation, Agamemnon, Menelaus’s brother, sacrifices his daughter Iphigenia to placate Artemis and procure favorable sailing winds during the Trojan War. Agamemnon’s wife, Clytemnestra, takes a lover—Aegisthus, son of Thyestes—while Agamemnon is away in Troy. Outraged at the sacrifice of her daughter Iphigenia, she plots revenge against her husband, while Aegisthus vows revenge for his father. When Agamemnon returns from Troy with Cassandra, the prophetess everyone always ignores, Cassandra foretells her and Agamemnon’s deaths but is unheeded. The two enter the palace, and Clytemnestra and Aegisthus kill them.

Two of Agamemnon’s children still live to perpetuate the bloodshed: his daughter, Electra, whom Aegisthus and Clytemnestra treat cruelly, and son, Orestes, whom a family friend has taken to protect him from Aegisthus. Orestes sets out for vengeance when he comes of age—even though he knows this means the terrible crime of matricide—and the Oracle at Delphi confirms him in this path. Returning to Mycenae, he runs into Electra, who is overjoyed and eager for him to avenge their father. Pretending to be a messenger bearing news of Orestes’ death, Orestes is welcomed into the palace, where he kills his mother and her lover. He instantly sees the terrible avenging Furies pursuing him, and he begins years of frenzied wanderings. Finally, with Apollo’s aid, he appeals to Athena, who pities him and turns the Furies into the Eumenides, “protectors of the suppliant.” The curse of the House of Atreus finally ends.

In another version of the story, Artemis grows horrified just before Iphigenia’s sacrifice and rescues her. Artemis brings Iphigenia to the land of the Taurians and makes her a priestess of her own temple. Regrettably, this job involves sacrificing humans, so Iphigenia goes about her duties very reluctantly. In this version, Athena has not completely absolved Orestes of guilt. The Oracle at Delphi tells Orestes that for his last cleansing act he must go to the land of the Taurians and procure the image of Artemis from its temple. Orestes and his friend Pylades set out on the quest, but the Taurians capture them almost immediately and intend to sacrifice them.

Orestes is taken to Iphigenia, the priestess, but the siblings fail to recognize each other because they have been separated for so long. Preparing Orestes and Pylades for death, Iphigenia asks where they are from. On hearing they are from Mycenae, she asks them about her family. She offers to set Pylades free if he takes a message to her brother, Orestes, telling him that she is alive and that he must rescue her. Orestes jumps up and reveals his identity. The three begin their escape with the image of Artemis. King Thoas of the Taurians pursues, but lets them escape when Athena says they are fated to do so.

hope this helps it broke it down for me
tiff xx