The Inachids were a royal family, the descendants of Inachus, a river-god and son of Oceanus and Tethys. They ruled both Mycenae and Argos and frequently intermarried with the House of Atreus, which succeeded them in both kingdoms. They are also the ancestors of the rulers of Thebes, Crete, Libya, Phoenicia and Cilicia. They have a cadet branche called the .