Ino is the daughter of Cadmus and Harmonia. Although Phoenician, Ino brought up Dionysus, the son of Zeus and her dead sister Semele.
Semele was one of Hera's victims, when Zeus' jealous wife tricked Semele in requesting her lover to come to her in his true form. This he did and appeared as lightning and thunderbolts and Semele was killed.
To hide the unborn Dionysus from Hera, he was taken from the womb and placed in Zeus' thigh until the time for his birth. Hermes, the messenger god, suggested that Dionysus is given to Ino to suckle and this was duly done.
However, Hera discovered the truth, as she normally did, and took revenge on Ino. She made Ino kill her own children, after which she killed herself by jumping of a cliff into the sea.