We usually think of Isis as an Egyptian goddess, but she was also worshipped by the Greeks after Alexander the Great conquered Egypt. When the Romans conquered both Egypt and Greece itself, the worship of Isis spread throughout the Roman Empire. She was venerated as a loving mother goddess who promoted fertility, oversaw the changing of the seasons, and healed the sick. She was also the patron of sailors. There were temples dedicated to Isis and her brother/husband Osiris throughout the Greco-Roman world. These temples were the sites of elaborate daily and annual rituals and were administered by an educated priesthood skilled in music and medicine. Isis worship was especially popular with women and with the new elite who gained wealth and prominence as the Roman empire expanded.
The Temple of Isis in Pompeii was small but ornate. It was destroyed in an earthquake in A.D. 62 but was rebuilt shortly after that. The renovation was financed by a freed slave in the name of his young son. There may have been political motivations for this since freed slaves were not allowed to hold public office, and the son who was appointed as a member of the city council was only six years old. The Temple has a mixture of Egyptian, Greek, and Roman architectural features. This is not surprising since Roman architecture of this period was very ornate, often used bright colors, and borrowed and mixed styles from many eras. There were many statues in the Temple of Isis and the portico walls were covered with elaborate murals. To the left of the temple was a small roofless structure containing a tank that may have held the sacred water from the Nile, which was very important in many Isis ceremonies. In the rear of the sanctuary was a room containing a marble table where sacred meals were probably served.
The Temple of Isis in Pompeii (2010)