Under the Greek Ptolemaic Dynasty and then Roman rule, Greeks and Romans introduced their own deities to Egypt. These newcomers equated the Egyptian gods with their own, as part of the Greco-Roman tradition of "interpretatio graeca". The worship of the native gods was not swallowed up by that of foreign ones. Instead, Greek and Roman gods were adopted as manifestations of Egyptian ones. Egyptian cults sometimes incorporated Greek language, philosophy, iconography, and even temple architecture. Meanwhile, the cults of several Egyptian deities—particularly Isis, Osiris, Anubis, the form of Horus named Harpocrates, and the fused Greco-Egyptian god Serapis—were adopted into Roman religion and spread across the Roman Empire. Roman emperors, like Ptolemaic kings before them, invoked Isis and Serapis to endorse their authority, inside and outside Egypt. In the empire's complex mix of religious traditions, Thoth was transmuted into the legendary esoteric teacher Hermes Trismegistus, and Isis, who was venerated from Britain to Mesopotamia, became the focus of a Greek-style mystery cult. Isis and Hermes Trismegistus were both prominent in the Western esoteric tradition that grew from the Roman religious world.