In Greek mythology, Nereus was the eldest son of Pontus and Gaia. Nereus and Doris became the parents of 50 daughters and a son, with whom Nereus lived in the Aegean Sea.
Nereus in a frieze of the Pergamon Altar (Berlin).
In Greek mythology, the Old Man of the Sea was a figure who could be identified as any of several water-gods, generally Nereus or Proteus, but also Triton, Pontus, Phorcys or Glaucus. He is the father
Nereus
…with whom Nereus lived in the Aegean Sea. The name Nereus is absent from Homer's epics; the god's name in the Iliad is the descriptive ἅλιος γέρων 'Old Man of the Sea', and in the Odyssey the combination of ἅλιος γέρων and Πρωτεύς 'Proteus'. Besides Nereus and Proteus, the descriptive "Old Man of the Sea" was used…
After being shipwrecked Sinbad the Sailor is enslaved by the "Old Man of the Sea".