In the multicultural world which succeeded Alexander's empire, the exchange of religious beliefs was more relevant than ever. From the 4th century BC onwards, the cult of Egyptian gods spread around the Mediterranean, and there are even testimonies suggesting a sanctuary dedicated to the goddess Isis was built in Piraeus during that century.
Herodes Atticus, a wealthy aristocrat, patron of the arts, and great benefactor of Attica and other regions, was born in Marathon in 101 AD. After a long career in politics, philosophy, and rhetoric, he returned to Greece, where he funded a host of public works most notably the Stadium and the Odeon at Athens.
Herodes was especially fond of his native land; the extensive repairs to the great temple of Nemesis may be safely attributed to him. In 160 AD, he commissioned the sanctuary of the Egyptian gods, dedicated to Serapis a Hellenised version of the god Osiris as well as his consort Isis and their son Horus. Built on an area roughly resembling a small island ( actually called Nisi Greek for 'island'), the sanctuary was probably an allusion to the Serapeum built by Hadrian on an artificial island in the grounds of his villa in Tivoli, Rome. In turn, Hadrian's temple was meant to recall the surroundings of the original Serapeum in Canopus, an Egyptian city at the western edge of the Nile Delta.
The main sanctuary (approx. 3,900 square metres) was surrounded by walls, and the four impressive entrances were adorned with pairs of statues both on the inside and out. Each pair consisted of one male pharaonic figure and one version of Isis as a Greek goddess most often Aphrodite (carrying roses) and Demetra (carrying cereals).
The complex also included luxurious Roman baths as well as a large oval fish pond which, together with the marble oil lamps of monumental size, are entirely unique in Greece.