The Lernaean Hydra: the Many-Headed Serpent Defeated by Heracles

Near Lerna, in the Argolid, not far from the coast of the Argolic Gulf, there once stretched a marshy area rich in springs. Here, according to myth, lived the Hydra, a many-headed water serpent that laid waste the countryside and killed the cattle. Its slaying is the second of the twelve labours of Heracles and one of the episodes most often represented in Greek and Roman art, from painted vases to sarcophagi.

A Daughter of Monsters

Hesiod, in the Theogony, presents her as the daughter of Typhon and Echidna, and therefore sister of Cerberus and of the dog Orthrus, and specifies that she was raised by Hera, hostile to Heracles, in order to harm him. The name Hydra comes from the Greek word for water and places her in the world of marshes and springs. The number of heads varies greatly from author to author: the sources speak of nine, fifty or even a hundred.

The Library attributed to Apollodorus, a mythological handbook of the Roman period, provides the fullest version. The Hydra had nine heads, eight mortal and one, the central one, immortal. Every time Heracles cut one off, two grew in its place. Its breath, according to some later sources, was so poisonous that it killed anyone who inhaled it, even while the monster lay asleep in its lair.

The Struggle and the Help of Iolaus

Heracles reached Lerna in a chariot driven by his nephew Iolaus. According to Apollodorus he forced the monster out of its lair by shooting flaming arrows at it and then fought it hand to hand. Hera meanwhile sent a giant crab that bit the hero's foot. Heracles crushed it, and according to tradition the goddess set it among the stars: it is the constellation of Cancer, which in the sky lies beside the very long constellation of Hydra.

To prevent the heads from growing back, Heracles called Iolaus to help, and he set fire to part of the nearby wood and with burning brands seared the freshly severed necks. Finally the hero cut off the immortal head and buried it under a heavy rock, beside the road that led from Lerna to Elaeus. Precisely because of the help he had received, Apollodorus says, Eurystheus refused to count this feat among the ten labours required.

The Venom That Killed the Hero

Heracles dipped his arrows in the Hydra's venom, making them deadly. Those arrows accompanied him in many later exploits, but they were also the cause of his end. With one of them he shot the centaur Nessus, who was trying to carry off his bride Deianira. As he died, Nessus deceived the woman, urging her to keep his poisoned blood as though it had the power to rekindle her husband's love.

Years later Deianira, jealous, dipped a tunic in that blood and sent it to Heracles. The Hydra's venom, still active, burned the hero's flesh with unbearable pain, until he had a pyre built on Mount Oeta and climbed onto it. It is one of the great tragedies of Greek mythology, told by Sophocles in the Women of Trachis: the vanquished monster, in the end, takes its revenge.

Over the centuries the Hydra has become the symbol of every evil that multiplies when one tries to fight it with inadequate means. In the eighteenth century Linnaeus gave the name Hydra to a tiny freshwater animal capable of regenerating parts of its body that have been cut off. Political and moral language has also adopted it, to describe problems that are not solved by striking one of their manifestations, but only by tackling their root.