A Memory of Wind By Rachel Swirsky

After Helen and her lover Paris fled to Troy, her husband King Menelaus called his allies to war. Under the leadership of King Agamemnon, the allies met in the harbor at Aulis. They prepared to sail for Troy, but they could not depart, for there was no wind.

Kings Agamemnon, Menelaus, and Odysseus consulted with Calchas, a priest of Artemis, who revealed that the angered goddess was balking their departure. The kings asked Calchas how they might convince Artemis to grant them a wind. He answered that she would only relent after King Agamemnon brought his eldest daughter, Iphigenia, to Aulis and sacrificed her to the goddess.

http://www.tor.com/index.php?option=com_content&view=story&id=58211