Ares is the god of war son of Zeus and Hera and Hercules' half brother.

He helped Xena to create the most powerfull army in the world and together they were unbeatable.Eversince Xena decided to follow the path of good Ares is trying to get her back because he wants her for himself but Gabrielle always kept Xena in the way of good. Probably that's why he dislikes her so much.

Ares betrayed the other Gods making an Alliance with Dahak and his daughter Hope.He even had a child with her . Xena tricked them into killing eachother.

In the end of season 5 Ares gives up his Godhood to save Gabrielle and Eves' (Xenas' daughter)life.Telling Xena he did it because he loved her and he wants her to give him another chance.