Iphigenia at Aulis

Ovid: Metamorphoses
Book XII

A thousand ships were launched, and all the Greeks,
Banded together, followed, and they would have
Taken their vengeance sooner, but the storms
Made the sea pathless, and Boeotia held them,
Impatient, at the little port of Aulis.

When here, as always, they had gotten ready
Their sacrifice for Jove, just as the altar
Glowed with the lighted fires, they saw a serpent,
Blue-green in colour, creeping up a plane-tree
Above them, toward a nest, high up, which held
Eight fledglings. These, together with the mother,
Flying too close to her doomed brood, the serpent
Seized and devoured. Amazement seized the people,
But the augur Calchas saw the meaning clearly:

"Rejoice, O Greeks: we shall win the war, and Troy
Go down before us, but our task will be
Of long duration: the nine birds mean nine years."

Meanwhile the serpent, coiled around the branches,
Was changed to stone, and the stone kept the form
Of the twining serpent.

                                       Nereus continued
Boisterous over the waves; he would not carry
The war across the sea, and there were people
Who thought that Neptune, who had built the walls
Of Troy, was therefore bound to spare the city.
Calchas knew better, and said so:"Virgin blood
Must satisfy the virgin goddess' anger."

The common cause was stronger than affection,
The king subdued the father;Agamemnon
Led Iphigenia to the solemn altar,
And while she stood there, ready for the offering
Of her chaste blood, and even the priests were weeping,
Diana yielded, veiled their eyes with cloud,
And even while the rites went on, confused
With darkness and the cries of people praying,
Iphigenia was taken, and a deer
Left in her place as victim, so the goddess
Was satisfied; her anger and the ocean's
Subsided, and the thousand ships responded
To the fresh winds astern and, with much trouble,
Came to the Phrygian shores.