1. Atreus and Thestes, rival brothers for throne of Argos
   
2. After Thestes seduced Atreus's wife, his children were served up to him unknowingly in a covered dish, but Aegisthis survived
   
3. Atreus had two sons, Agamemnon, leader of the fleet in the Trojan war, and Menelaus, husband of Helen, whose abduction by Paris started the war
   
4. Agamemnon married Clytemestra (sister of Helen) and had three children, Iphigenia, Orestes, and Elektra.
   
5. When the fleet was becalmed, the goddess Artemis through Calchas requested the sacrifice of Iphigenia.
   
6. The destruction of Troy (Ilium) was excessive and the homecomings of the Greeks (Archeans, Argives) was delayed
   
7. During the war Agamemnon and Achilles had quarreled over the possession of captive princesses as trophies
   
8. Agamemnon returned home with his captive Cassandra, daughter of King Priam of Troy, empowered with prophecy
   
9. Meanwhile Clytemestra had taken Aegisthus as her lover and had exiled Orestes
   

The play

1. Returning home without suspicion and subject to flattery, Agamemnon is killed in his bath by Clytemestra (Cassandra is also murdered)
   
2. Apollo orders Orestes to avenge his father's murder by killing Clytemestra, his mother, and her lover Aegisthus
   
3. In turn, the ancient Furies seek revenge on Orestes but are restrained by Apollo, who refers the case to Athena
   
4. Athena invents and summons a jury, which is deadlocked, whereupon she casts the vote exonerating Orestes
   
5. The enraged ancient Furies are pacified, converted into gentle Eumenides (kindly family guardians)
   

Sidelights

1. Parallels of Agamemnon and Achilles
   
2. Contrast of impetuous and prideful Agamemnon and careful, prudent Odysseus as Greek chieftains (tragedy vs. epic)
   
3. Parallels: a)sisters Clytemestra and Helen, b)wives Clytemestra and Penelope

Alternate names

1. Apollo; Loxias, Phoebus,sun
2. Athena: Pallas. Minerva (Roman)
3. Atreide: sons of Atreus
4. Paris: Alexander

   Family Tree (Simplified)
   Tantalus
   |
   Pelops
   |
   ---------------------
   Thyestes          Atreus
   |           ________ |__________
   |                                 |                                     
   Aegisthus        Menelaus    Agamemnon
                    (= Helen)   (= Clytaemnestra)
                           _______________|______________
                           |               |           |
                         Iphigeneia      Electra    Orestes