Phoroneus was the son of the river god Inakhos and either the ash-tree nymph, Melia, or Argia, the embodiment of Argolid itself. He was possibly married to Cerdo, Teledice, Perimede, Peitho, or Europa. Niobe is also linked to him as either his mother, daughter, or wife. He was the primordial king of the city of Argos, and a hero of the area. He gathered the people of the area into a community, and taught them how to create fire and use the forge.
After his death, Jasus and Pelasgus divided his kingdom in two. Pelasgus founded and became the ruler of the city of Larissa, while Jasus ruled over Elis. After their deaths, Agenor invaded both regions and ruled over them.