Cecrops I

Cecrops /ˈsiːˌkrɒps/ (Ancient Greek: Κέκροψ, Kékrops; gen.: Κέκροπος) was a mythical king of Athens who, according to Eusebius reigned for fifty years. The name is not of Greek origin according to Strabo, or it might mean 'face with a tail': it is said that, born from the earth itself, he had his top half shaped like a man and the bottom half in serpent or fish-tail form. He was the founder and the first king of Athens itself, though preceded in the region by the earth-born king Actaeus of Attica. Cecrops was a culture hero, teaching the Athenians marriage, reading and writing, and ceremonial burial.

He is said to have been the first who deified Zeus, and ordained sacrifices to be offered to him as the supreme Deity. He is likewise affirmed to have been the first who set up altars and statues of the gods, offered sacrifices, and instituted marriage among the Athenians, who, before his time, it seems, lived promiscuously. Pausanias tells us that he forbade the sacrificing of any living creatures to the gods, as well as any sort of other offering, only allowing cakes formed into the shape of an ox with horns, called by the Athenians Pelanous, which signifies an ox. He is likewise said to have taught his subjects the art of navigation; and, for the better administration of justice and intercourse among them, to have divided them into the four tribes called Cecropis, Autochthon, Actea, and Paralia. Some likewise make him the founder of the areopagus.

During his reign, Athena became the patron goddess of the city of Athens in a competition with Poseidon. The two raced ferociously towards the Acropolis. It was a very close race, but Athena, as judged by Cecrops, won. As evidence of her victory she planted an olive tree. Poseidon arrived moments later, struck the acropolis with his trident and thereby created a salt sea. But Athena had already won, and the city was hers.

...
Wikipedia