Despoina

In Greek mythology, Despoina, Despoena or Despoine, was the daughter of Demeter and Poseidon and sister of Arion. She was the goddess of mysteries of Arcadian cults worshipped under the title Despoina, "the mistress" alongside her mother Demeter, one of the goddesses of the Eleusinian mysteries. Her real name could not be revealed to anyone except those initiated to her mysteries. Pausanias spoke of Demeter as having two daughters; Kore being born first, then later Despoina. With Zeus being the father of Kore, and Poseidon as the father of Despoina. Pausanias made it clear that Kore is Persephone, though he wouldn't reveal Despoina's proper name.