The legend was this: It seems that one of the ancient and long-venerated gods of the Egyptians was a deity named Serapis.

He had been, among other divinities, the object of Egyptian adoration ages before Alexandria was built or the Ptolemies reigned.

There was also, by a curious coincidence, a statue of the same name at a great commercial town named Sinope, which was built upon the extremity of a promontory which projected from Asia Minor into the Euxine Sea.

Sinope was, in some sense, the Alexandria of the north, being the center and seat of a great portion of the commerce of that quarter of the world.
The Serapis of Sinope was considered as the protecting deity of seamen, and the navigators who came and went to and from the city made sacrifices to him, and offered him oblations and prayers, believing that they were, in a great measure, dependent upon some mysterious and inscrutable power which he exercised for their safety in storms.

They carried the knowledge of his name, and tales of his imaginary interpositions, to all the places that they visited; and thus the fame of the god became extended, first, to all the coasts of the Euxine Sea, and subsequently to distant provinces and kingdoms.