Peace at Last?

I have two cats - Sami and Romeo. Sami is 10 and Romeo is 5. I've had both since they were kittens. Sami has been extremely jealous of Romeo since he's been part of our household and has become a bully, bullying Romeo. Romeo doesn't take lightly to the bullying and fights back. Sami has bitten the outer layer of Romeo's ear off. Now one of Romeo's ears is slightly smaller than the other. Romeo has usually taken the brunt of Sami's bullying. Romeo is a bit older now, outweighs Sami by 4-1/2 pounds and defends himself. The other day I noticed blood in Sami's ear. Took him to the vet who put him on antibiotics. He was laying low and even sort of hiding. He completely left Romeo alone; however, Romeo saw his chance to get back and chased him round and round for a few days. Then....peace...quiet! I thought that now Sami learned his lesson and would now try to get along with Romeo. Well, the peacefulness lasted about 3-4 days during which time Sami was healing. I knew when I heard loud growling and cat fighting and hissing noises again that Sami had healed and was back to bullying Romeo and found Romeo couldn't be bullied so easily. Romeo now bullies Sami - they take turns bullying each other. Peace? No such luck!
Does anybody have any ideas as to how to get these two to leave each other alone and just get along? I'm ready to try anything short of giving one or the other to someone else. My body can't take too many more scars.