Hera was born to Cronus and Rhea, the Titan rulers who had swallowed their own children to prevent a prophecy that one of them would overthrow the father. Zeus, her youngest brother, was hidden away on the island of Crete and grew to adulthood in secret. When he returned to challenge Cronus, he forced the Titan to vomit up his swallowed children: Hestia, the goddess of the hearth; Demeter, the goddess of grain; Hera herself; Hades, the grim lord of the dead; and Poseidon, the god of the sea. The siblings united against their father in a war called the Titanomachy, the war between the old Titans and the young Olympian gods, and after ten years of battle they cast Cronus down and divided the world among themselves. Zeus took the sky, Poseidon the sea, Hades the underworld, and Hera became the queen of Olympus, the bride of Zeus in a marriage that would define the politics of heaven for eternity.

The wedding of Zeus and Hera was celebrated with a feast that lasted three hundred years, and the earth itself blossomed in joy. But the joy did not last. Zeus was incapable of fidelity. He pursued mortal women, nymphs, goddesses, and even other men's wives with relentless appetite. Hera, whose very domain was the sanctity of marriage, could not tolerate this. She did not weep or plead. She struck back. When Zeus fell in love with the mortal woman Alcmene, Hera delayed the birth of her son Heracles so that a rival heir would be born first, and then sent serpents to kill the infant in his cradle. When the boy grew to manhood and became a hero, Hera drove him mad. In his frenzy, Heracles murdered his own wife Megara and their children, a crime that would haunt him for the rest of his life and force him to complete twelve impossible labors as penance. Every labor was made harder by Hera's interference. She sent monsters against him, raised storms, and turned allies against him. Her hatred was not personal against Heracles as a man; it was absolute against him as the living proof of Zeus's betrayal.

In the Trojan War, a conflict that began when Paris, a Trojan prince, awarded a golden apple to Aphrodite, the goddess of love and beauty, rather than to Hera or Athena, the goddess of wisdom and war, Hera's vengeance knew no bounds. She hated Troy with a ferocity that shocked even the other gods. She bribed Sleep, the personification of slumber, to put Zeus into a deep unconsciousness so she could manipulate the battle without his interference. She seduced him with charms borrowed from Aphrodite herself, then while he slept she turned the tide of war against the Trojans. She armed the Greeks, inspired their warriors, and even descended to the battlefield in disguise to rally the troops. When Zeus woke and discovered what she had done, he raged and threatened to hang her from Olympus by golden chains, but she did not flinch. She had been queen too long to fear his temper. The war dragged on for ten years, and Hera made sure that every Trojan death was a payment for the insult of Paris's choice.

Hera's cruelty was not indiscriminate. She was a protector of married women and a guardian of legitimate children. Women in labor prayed to her, and cities that honored marriage and family built her temples with special devotion. The island of Samos was sacred to her, and her temple there was one of the largest in the Greek world. At Argos, her ancient sanctuary was served by a priestess who held the office for life and wielded political influence that rivaled kings. The peacock became her sacred bird after the death of Argus, the hundred-eyed giant whom she had set to watch over the maiden Io, one of Zeus's lovers whom the king of gods had transformed into a white heifer to hide her from his wife's wrath. Hera knew the trick. She sent Argus to watch the cow, and his hundred eyes never all closed at once. Zeus sent Hermes, the messenger god who moved between worlds, to kill Argus, and Hermes lulled the giant to sleep with music before striking him down. In grief and honor, Hera took Argus's hundred eyes and placed them upon the tail of the peacock, where they remain to this day, watching still.

Hera bore Zeus several children: Ares, the god of war, whom even his parents found brutal and unpleasant; Hebe, the goddess of youth who served nectar to the gods; Eileithyia, the goddess of childbirth; and Hephaestus, the crippled smith whom she cast from Olympus in disgust at his deformity. Some say she conceived Hephaestus alone, without Zeus, in retaliation for his birthing of Athena from his own head. The story of her rejection of Hephaestus would return to wound her when the grown god trapped her in a golden throne, and she was forced to swallow her pride to beg for release. In the Roman world, the Greeks identified her with Juno, the queen of the Roman gods and the protector of the Roman state. The month of June is named for her, and weddings in that month still carry her ancient blessing. She remains the most complex of the Olympians: a goddess of loyalty who was betrayed, of marriage who was mocked, of power who was constrained by the very throne she shared. Every quarrel between husband and wife, every legitimate child born in wedlock, every jealous glance across a crowded room, belongs to her domain.