Atreus in Wikipedia

In Greek mythology, Atreus (Ἀτρεύς) was a king of Mycenae, the son of Pelops and Hippodamia, and the father of Agamemnon and Menelaus. Collectively, his descendants are known as Atreidai or Atreidae. Atreus and his twin brother Thyestes were exiled by their father for murdering their half-brother Chrysippus in their desire for the throne of Olympia. They took refuge in Mycenae, where they ascended to the throne in the absence of King Eurystheus, who was fighting the Heracleidae. Eurystheus had meant for their stewardship to be temporary, but it became permanent after his death in battle...

Read More about Atreus in Wikipedia