Nereus is said to be a marine deity that predates the god Poseidon. Ancient Greek traditions and almost all ancient Greek poets and artists portray Nereus as an old man, a meek, kind and lovable man. His wife was the Oceanid Doris with whom he had the numerous genus of Nereids, the beautiful daughters fifty in number or a hundred according to more recent traditions.
Nereus had the gift of divination, it is said that he foretold to Paris when he kidnapped Helen the destruction of his country as a result of his evil deed. As all sea deities could transform themselves, so Nereus transformed himself into strange and unlikely shapes
Nereus was also the one who showed Hercules the way to the garden with the golden apples of the Hesperides by fighting with him to achieve it.
The name Nereus has a clearly defined meaning and reminds us of moving water. Nereus is referred to in Homer and Hesiod in such a way that it is easy to understand its characteristics, which the human mind conceived from the various forms of the sea. For example, from the white foam on the tops of the waves people imagined Nereus as an old man, and his popular name was γέρων άλιος[1].
Sailors are not afraid of Nereus because his power is beneficial. According to Theogony, Nereus is an old man and lies do not touch him, he is soft and deserves only trust as his mind generates only righteous thoughts. It appears from this, therefore, that the person of Nereus is the manifestation of one of the aspects of the sea, the sea that is good for man, that does not deceive him with false promises and which is offered to him for his prosperity.
The expressive names we derive from Theogony for the fifty Nereids, the daughters of the old Nereus, refer precisely to the various forms (state of the sea) and graces of the sea. They recall the benefits of the sea, the riches it gives to man and the ease it provides in trade