Briseis

Description
Taken captive by the Greeks in their raids on the Trojan countryside, Briseis was given as a war-prize to Achilles. When Achilles defied him, Agamemnon confiscated her as a punishment. She was returned after Patroclus’ death, and in Book 19 of the Iliad, she and the other women of the camp mourn over his body. 

Patroclus
Patroclus didn't want Briseis to be afraid of him or Achilles raping her, so he kissed Achilles in front of her to make her understand. She quickly learned their language and became a close friend of Patroclus. She seems to have had a crush on him. Briseis tells Patroclus that if their camp falls, she will claim Patroclus as her husband so that perhaps they will not kill him. He tells her that if the camp falls, he will be with Achilles.