Ino married King Athamas of Orchomenus on the western shore of Lake Copais, capital of Boetia. Athamas married Ino after tiring of his first wife Nephele. Upon hearing that Athamas was taking another wife, Nephele complained bitterly to Hera about Athamas' infidelity.
One year the crops went bad and the famine hit Orchomenus hard, so Athamas sent messengers to the Delphi Oracle to see what could be done to stop the famine. Ino secretly bribed the messenger to come back with the message that Athamas must sacrifice his son by Nephele, Phrixes. Ino did this out of her selfish desire to see one of her two sons with Athamas, Learchus or Melicertes, receive the kingdom at Athamas' death. Athamas had Phrixes on the altar and was about to sacrifice him when a golden ram appeared by the altar. Phrixes and his sister Helle climbed on the ram's back and they flew towards the east. As the ram was going over the straits between the northern Aegean and the Propontis, Helle fell off of the rams back into the straits below and that is why that spot is still called Hellespont. The ram kept flying until it reached Colchis in the land of Aea at the eastern end of the Black Sea. Here, Phrixes sacrificed the ram to Zeus to show his appreciation for being delivered from Ino's vengeance. Phrixes gave the skin to Aeetes, the king of Aea. This is one story of the origins of the Golden Fleece that Jason is sent to retrieve for Pelias.
As revenge for Nephele and for Ino raising Dionysus, Hera struck Athamas. Athamas, thinking that Learchus was a ram, shot an arrow through Learchus then tore his body to pieces. Ino, like any frightened mother, took her other son, Melicertes and fled the castle. With Athamas in hot pursuit, Ino ran to the Molurian Rock where she desperately jumped into the river below, drowning herself as well as Melicertes. Zeus, not wanting Ino's ghost to go to Tartus for she did raise his son Dionysus, turned Ino into the sea deity, Leucotha (white goddess) and Melicertes into Palaemon.
Another version of the story has Hera afflicting both Ino and Athamas with madness. Ino boils Melicertes in a cauldron, than picks up the cauldron and flees. Then she jumps over the cliff with the cauldron still in her arms.
The madness caused within Ino's house can be attributed to her association with Dionysus. It seems that no one can escape the effects of being around Dionysus. People who resist him are turned mad in fits of Bacchae madness, and people who follow him are also afflicted with the madness.