Alcippe was born from the union of Ares and Aglaurus, the daughter of Cecrops, the legendary early king of Athens. This Aglaurus is the princess, not her mother of the same name, who was a daughter of Actaeus. Apollodorus places Alcippe within that family, linking her through her mother to Herse and Pandrosos and through her father to the Olympian gods. She belongs to the legendary ancestry of Athens, a family in which the origins of the city were closely joined to the actions of divine beings.

Aglaurus also appears in the story of the chest entrusted by Athena to the daughters of Cecrops. It contained the infant Erichthonius and was not to be opened. The sisters' disobedience and its consequences were told in different ways, so the chest story does not supply one fixed chronology for Alcippe's birth. What remains clear in the genealogy is her mother's identity. Alcippe joins the household of the city's first kings to Ares, a god more often remembered for warfare than for the defence of a daughter.

The attack brought that family into conflict with Poseidon's son Halirrhothius. Apollodorus names his mother as the nymph Euryte and says that Halirrhothius tried to rape Alcippe. Ares caught him and killed him. Pausanias gives a version in which the sexual assault had taken place before the killing, and associates it with a spring near the Acropolis. The accounts therefore differ over whether the assault was attempted or completed. In both, it was the reason that Ares acted against Halirrhothius.

Poseidon accused Ares over the death of his son. The conflict was no longer only an encounter between an attacker and an intervening father: it had become a dispute among the gods over responsibility for a killing. According to Apollodorus, Ares was tried on the Areopagus before twelve gods and acquitted. The surviving narrative is brief and does not preserve a speech by Alcippe or explain the judges' deliberations. Her experience remains central to the case even though the account gives most of its attention to the two fathers and the outcome.

Pausanias explains the name Areopagus, the Hill of Ares, through this trial. He then places the later legendary trial of Orestes for killing his mother within the same sacred landscape. In his description, stories of divine and heroic bloodshed belong to a real Athenian place associated with homicide proceedings. The hill and the nearby spring gave Alcippe's story a presence in the city that visitors could be shown long after its supposed heroic age. The legend explained why such a place belonged to the judgement of bloodshed; it was not a surviving historical record of the court's foundation.

The Parian Chronicle also includes the dispute between Ares and Poseidon in its retrospective chronology of the distant past. Its placement among early kings belongs to an ancient effort to arrange legend and history within one sequence. Alcippe herself receives no comparable account of later events: the principal narratives considered here supply no subsequent marriage, children or death. What survives is a moment of harm, intervention and judgement. That moment can prompt reflection on protection and responsibility without making Alcippe the direct founder of modern law or attributing words to her that the ancient sources do not preserve.