In The Iliad, the first of many quarrels between Agamemnon and Achilles is ignited by Briseis and Chryseis. Because Agamemnon is forced to relinquish his prize, Chryseis, he demands Achilles to give up his own war prize, Briseis, as shown in the following quote:
But let this be my warning on your way: Since Apollo insists on taking my Chryseis, I'll send her back in my own ships with my crew. But I, I will be there in person at your tents To take Briseis in all her beauty, your own prize So you can learn just how much greater I am than you (Homer, I. 215-219)
This angers Achilles so greatly that he nearly kills Agamemnon, but is narrowly stopped in time by Athena. While Troy portrays the tension between Achilles and Agamemnon, it does not provide the same explanations for the animosity as the book does. Rather, the character of Briseis is given most of the credit for their fragile relationship. In the movie, the warrior and the king fight over Briseis, and when that argument is ended with Achilles finally getting his way, he is so distracted by her that it nearly costs the Achaeans the entire war. As Odysseus, played by Sean Bean, says, "Women have a way of complicating things." It is true that Briseis is a character from the book, however she does not play as large of a role in the story as the character