Halirrhothius was the son of Poseidon and Euryte (or Bathycleia) in Greek mythology. When Halirrhothius raped Alcippe, Ares's daughter by Aglaulus, Ares murdered him; Ares was tried in a court made up of his fellow gods. The trial was held on a hill adjacent to the Acropolis of Athens, known as the Areopagus. Ares was acquitted.