Dealing with rooster behaviors can be a bit complex. Especially when you have multiple roosters. I have 7 roosters right now, (1 adult rooster and 6 cockerels). Can you give more information on your chicken accommodations?
How many hens do you have?
How many roosters/cockerels do you have?
Do your roosters fee range?
How old are the roosters?
If your roosters live together, removing one, for more than a few hours will upset the pecking order of the roosters. You most likely will not be able to reintegrate the rooster that you remove from the flock. The other rooster(s) will attack him.
Roosters have to be managed carefully, especially when they are young. Like hens, multiple roosters must establish a pecking order among themselves, if they are in the same pen. Peck wounds on the comb and wattles do happen. If they have bloody fights everyday, then, you may have to put one of the roosters in another pen with shelter. Since he cannot live by himself, indefinitely; you'll need to get some hens for him. Another option is to re-home one of the roosters.
These are my views on your rooster issue. I hope I have been helpful.
Got him in a separate area now... I'm thinking it was the younger rooster that hatched out last spring. They are the same breed (leghorn/road island red mix). I have other roosters (reds) that don't mix it up with the leghorn/reds. Is it possible leghorns are more jealous/territorial? Well, I guess all I can do is keep Foghorn isolated and try to let him out after a while... If it happens that they start fighting again, someone will have to go...
I've got ~16 hens, ~4 roosters. All free range. Roosters from 1 to ~4 years.
I'm incubating the hens eggs in spring and summer, so it's hard to keep track of ages.
All my reds seem to get along. Foghorn got along with the reds... this just happened now with the new leghorn mix. oh well, life on the farm...
Your other bird decided to challenge him for the top spot, your others did not do so. Very common rooster behavior, especially when you have a younger bird becoming mature. These battles can sometimes be very bloody and brutal with serious injuries.