This concept of deity was the result of a fusion of the Egyptian god Osorapis (OSIRIS/APIS) with the attributes of a number of Hellenistic gods, Zeus, Helios, Hades, Asklepios and Dionysos. Osorapis had solar, funerary, healing and fertility aspects. He protected the corn supply.

Serapis is first attested to in the reign of Ptolemy I Soter (305-285 BC) and was considered to be the essense of the Egyptian religion blended with the Greek theology. The main cult was not Memphis, but the Alexandrian SERAPEUM. This was an important center of learning. His consort was Isis, who was very popular among the Romans. The pair came to embody the natural forces of male and female fertility. They were sometimes represented as human headed serpents. The bearded one was Serapis. The cult speard widely through out the Roman Empire. The Romans kept alive the the animal deities they initially despised.