Excerpts taken from the Oxford Classical Dictionary:

The greatest of Greek heroes. His name is that of a mortal and has been interpreted as "Glorious through Hera." Heracles is in fact harassed rather than protected by the goddess Hera. Heracles shared the characteristics of, on the one hand, a hero (both cultic and epic), on the other, a god. As a hero, he was mortal, and like many other heroes, born to a human mother and a god, Zeus. Zeus's wife, Hera, pursued Heracles with implacable enmity from before his birth, then sent serpents to attack Heracles in his cradle. Later, she drove him mad and caused him to murder his Theban wife and their children. Heracles took part in the Trojan war, accompanied the Argonauts, and founded the Olympian games. Heracles is famous for his 12 Labours, amongst which he defeats a lion, a Hydra, a boar, a bull, and travels to the flames of the underworld, Hades, where he encounters Charon and defeats Cerberus.