What was the main reason for Orestes’ actions in Aeschylus's Eumenides?

In Aeschylus's "Eumenides," Orestes' main motivation for his actions is rooted in the quest for revenge for his father's murder, specifically that of King Agamemnon. According to the story, Orestes is driven by a sense of duty and familial obligation to avenge his father's death, which was orchestrated by his mother, Clytemnestra, and her lover, Aegisthus. This act of revenge is not merely a personal vendetta but is deeply connected to themes of justice and moral order within the context of Greek tragedy. Orestes' actions also highlight the complexities of vengeance and the transition from a cycle of retribution to a more structured judicial system, as seen later in the play's resolution and the establishment of the court. His motivations reflect a broader narrative of grappling with justice, fate, and the consequences of familial loyalty, making revenge for his father's murder the central catalyst for his actions in the narrative.