In Greek mythology, Erichthonius was a legendary early king of Athens. According to the myths he was autochthonous — born of the soil or Earth — and was adopted and raised by the goddess Athena. Early Greek texts did not distinguish him from his grandson Erechtheus, but by the fourth century BC, in Classical times, the two were treated as separate figures.
Adapted from Wikipedia, "Erichthonius of Athens" · CC BY-SA 4.0
I.Etymology
The name Erichthonius is of uncertain origin and is probably pre-Greek. The familiar link to the Greek verb ἐρέχθω (erékhthō, "to shake") is generally treated as a late folk-etymology rather than a genuine derivation.
Other folk-etymologies break the name into a first element — either ἔριον (erion, "wool") or ἔρις (eris, "strife") — joined to χθών (chthōn, "earth"). These readings echo the story of his conception, in which Athena wipes Hephaestus's seed away with a scrap of wool and casts it to the ground. Beekes (2009) argued instead for a pre-Greek proto-form reconstructed as *Erektyeu-.
II.Mythology — Birth
According to the Bibliotheca, Athena came to Hephaestus wishing to have weapons made. Overcome with desire, Hephaestus pursued and tried to force himself on her, but she resisted. In the struggle his semen fell upon her thigh; Athena wiped it away with a scrap of wool and flung it to the earth. From this seed, fallen on the ground, Erichthonius was born — making him a child of Hephaestus and of Gaia (the Earth), and so autochthonous.
Athena placed the infant in a box (or basket) and gave it to the three daughters of Cecrops — Herse, Aglaurus, and Pandrosus — with strict instructions never to look inside. Pandrosus obeyed, but the other two sisters opened the box. Inside they saw either a serpent coiled around the infant or a child that was part human and part serpent. Horrified, they went mad and threw themselves from the Acropolis to their deaths.
In an alternative account, Athena was carrying a limestone mountain from Pallene to fortify the Acropolis when a crow brought her the news that the box had been opened. In her rage she dropped the mountain where it stands today as Mount Lycabettus.
III.Mythology — Reign
On reaching adulthood, Erichthonius drove out Amphictyon — who had earlier usurped the throne from Cranaus — and became king of Athens. He married the naiad Praxithea, by whom he had a son, Pandion I.
During his reign Erichthonius founded the Panathenaic Festival in honour of Athena and set up a wooden statue (xoanon) of the goddess on the Acropolis. According to the Parian Chronicle, he taught his people to yoke horses and use them to draw chariots.
Being lame, Erichthonius is credited with inventing the quadriga, the four-horse chariot, which gave him mobility, and he became a skilled charioteer. Zeus was said to have been so impressed with his skill that after his death he raised him to the heavens as the constellation Auriga, the Charioteer.
The snake is Erichthonius's symbol and appears coiled behind the shield of Athena's statue in the Parthenon. The Erechtheum, the most sacred building on the Athenian Acropolis, is associated with him, and he was succeeded by his son Pandion I.