Despoina or Despoena (dɛs'piːnə; Déspoina) was the epithet of a goddess worshiped by the Eleusinian Mysteries in Ancient Greece as the daughter of Demeter and Poseidon and the sister of Arion. Surviving sources refer to her exclusively under the title Despoina ("the Mistress," cognate of "Despot") alongside her mother Demeter, as her real name could not be revealed to anyone except those initiated into her mysteries and was therefore lost with the extinction of Eleusinian religion. Writing during the second century A.D., Pausanias spoke of Demeter as having two daughters; Kore being born first, before Despoina was born, with Zeus being the father of Kore and Poseidon as the father of Despoina. Pausanias made it clear that Kore is Persephone, although he did not reveal Despoina's proper name. In the myth, Poseidon saw Demeter and desired her. To avoid him, she took her archaic form of a mare, but he took the form of a stallion and mated with her. From this union Demeter bore a daughter, Despoina, and a fabulous horse, Arion. Due to her anger at this turn of events, Demeter also was given the epithet Erinys (raging). The first element of the name Des-poina is derived from the PIE root *dem- meaning "house, household", Sanskrit damah "house;" Avestan demana- "house;" Greek domos "house,; Latin domus "house". Related words despotēs "master, lord;" Latin dominus "master of a household;" Armenian tanu-ter "house-lord " The second element is derived from the hypothetical PIE form *, "mistress", "lady", "wife", is the feminine counterpart to *pótis, "husband"; cf. Latin ho, "host", Sanskrit , "master", "husband", fem. , "lady", "wife". The Greek female equivalent for despotēs was despoina "lady, queen, mistress," source of the fem. proper name Despina. (Etymologically the "mistress of the house"). Related attested forms, written in the Linear B syllabary, are the Mycenaean Greek , po-ti-ni-ja, (potnia) and perhaps , po-se-da-o, and , po-se-da-wo-ne (Poseidon), which were inherited into classical Greece with identical or related meanings.