First example that pops to mind:
(this is how I figure things like this out. I figure out what other people have done that's similar, find the reasons for that situation, and then twist them to fit a different situation. Idea digging.

) [end ramble]
what pops to mind is the BBC series; Merlin. (who recommended that? Come forward!!!)
Uther hates magic. He thinks magic is evil. He has anyone even suspected of even talking to a sorcerer or a variation thereof, executed. He kills a lot of innocent people this way. His ward, Morgana, in one episode, shelters a Druid boy that Uther is looking for. She knows that if he's found she and the boy will be executed. Her position
might save her, but that's a big if. So it's a similar situation.
Short equation: the ruler of race B (humans) hates the religion/beliefs/cobha of race A.
(In the series magic is often something you are born with. Morgana eventually realizes she has magic, she's scared, frightened, has grown up believing it to be evil and doesn't know what to do. That's just to justify my Idea Mine here.)
So there's one idea for you.
As far as names go, we need something to build off of. What are some names of some characters? What is this race like? How are they different from humans? Maybe it's a racist thing. Like take our modern racist problem (blacks and whites) and magnify it. Maybe one race is considered by the other to be inferior "sub-human". You need something deeper than politics to make it that widespread; something bred into their very culture.
Is it a one way situation or do both races feel that way about each other? I read another book, "White Midnight" where Race A were farmers, cultured, civilized, etc, and they were constantly raided by the Dalradians (race B, an american indian type race.) The Dalradians would rape women, and if a child was born, it was considered an abomination and sent into the wilderness to die. However, the Dalradians didn't mind taking in a half blooded child as one of their own. One girl in the story defies all tradition and marries a Dalradian. Her father kills her husband and locked her in a room by herself to give birth, not allowing her to have any attendants, in case the child had blue eyes, and everyone learned the truth. (Dalradians had blue eyes, the homelanders had brown eyes.) There's never even any reason given why the two races hate each other so.
Hope that helped some.
