1. One of the giants, a son of Uranus and Ge. During the fight between the giants and the gods, when Porphyrion intended to offer violence to Hera, or, according to others, attempted to throw the island of Delos against the gods, Zeus hurled a thunderbolt at him, and Heracles completed his destruction with his arrows. (Apollod. i. 6. § 1, &c.; Pind. Pyth. viii. 12; Horat. Carm. iii. 4. 54; Claudian, Gigantom. 114, &c.)

2. According to a tradition of the Athenians, the most ancient king in Attica; he is said to have reigned even before Actaeus, and to have introduced into Attica the worship of Aphrodite. (Paus. i. 2. § 5, 14. § 6.)