Chronicling the deeds of great heroes from the past who helped form a society, the Iliad is an epic poem. As such the epic stands as a bridge between history and literature. As was the tradition in epic poetry, the Iliad opens in medias res, meaning "in the middle of things," although the action is always preceded by the poet's invocation to the muse (the goddess) of poetry. In this invocation, Homer states his theme — the wrath, or the anger, of Achilles and its effects — and requests the aid of the muse so that he can properly recount the story. The reader is then carried to the point where the trouble originally arose, which is where the story of the Iliad actually begins: in the middle of war.
During one of the Achaian (Greek) army's many raids on the cities located near Troy, the Achaians captured two beautiful enemy maidens, Chryseis and Briseis. The troops awarded these girls to Agamemnon, the commander-in-chief of the army, and to Achilles, the Achaians' greatest warrior.
Chryses, the father of Chryseis, pleads for her return but Agamemnon denies the plea. Consequently, Chryses prays to Apollo who brings a plague on the Achaian camp. On the tenth day of the plague, Achilles can wait no longer for King Agamemnon to act to end the plague. Usurping Agamemnon's authority, Achilles calls an assembly of the army, and he suggests that a soothsayer be called upon to determine the cause of Apollo's anger. Kalchas, an Achaian soothsayer, volunteers to explain the cause of the pestilence, but only if he is guaranteed personal protection. Achilles agrees to this condition.
