Achilles and Agamemnon --> The Iliad

Achilles 

  Agamemnon

Agamemnon and Achilles were fighting over a girl.  Agamemnon took Chryseis, daughter of Chryses as a war prize.  The god Apollo was mad because Chryses is his priest.  Agamemnon 

agreed to give Chryseis back, but in exchange for Achilles war prize.  That's all I really know, it was rather confusing without Ms. Rokicki explaining.  It was Agamemnon's fault.