In Greek mythology, Proteus (/ˈproʊtiəs, -tjuːs/; Ancient Greek: Πρωτεύς - protos, "first") was an ancient Egyptian king who was associated with the island of Pharos, his residence in Homer's Odyssey. Virgil, however, instead of Pharos, mentions the island of Carpathos, between Crete and Rhodes. This Greek island is the closest to Pharos geographically.
The name of Pharos may be a Greek adaptation of the title Pharaoh. Also, 'Proteus' may be based on one of the titles of Egyptian king, Prouti, signifying the "high doors" of the temple.
Proteus also seems to have been associated with Thrace, and legends portray him as coming from Thrace to Egypt, or as going from Egypt to Thrace.
There's also some sort of association of Proteus with the island of Lemnos, close to Thrace.
Herodotus invoked Proteus in his telling of the story of Helen of Troy. In Book II of The History, the story is told of how Proteus rose to the throne of Egypt out of Memphis, succeeding Pheron as king. He was later succeeded by Rhampsinitus (Ramesses III, as he was known by the Egyptians). When Paris stole Helen from Sparta, winds blew him off his intended course and he found himself in Egypt. Upon their arrival, Paris and his servants discovered a temple, in which the slaves realized it would be profitable for them to take refuge. Thus, they deserted Paris, informing the authorities of his numerous wrongdoings. Word of Paris' crimes reached Proteus, who then requested Paris be brought forth for inquiry. Proteus asked Paris for the details of his journey, ultimately concluding that despite his anger and Paris' terrible actions, he cannot kill a man who is a stranger from another land. Instead of death as Paris' punishment, Proteus took Helen from Paris and seized the treasure stolen from Menelaus, intending to return both Helen and the treasure to Menelaus, to whom they were rightfully due. Proteus then urged Paris to leave Egypt.