In ancient times, the worship of a god of partly human and partly divine origin, such as the worship of the hero Hercules. Hero-cult worship was the forerunner of the worship of living rulers, a feature of Hellenistic and Roman times. The hero cult invested a dead man with divine qualities of intelligence and strength which made him worthy of being honored by a cult. The founders of the city-states (such as Theseus at Athens) were often heroized. One basis for belief in heroes and the hero cult was the idea that the mighty dead continued to live and to be active as spiritual powers from the sites of their graves. Another source of the cult of heroes was the conception that gods were often lowered to the status of heroes. One of the best known heroes is Heracles, who became famous through his mighty deeds.