You all got it wrong... you see it is because Eponllyn doesn't like having a realm run as a tyranny next door...
Sirion have tried to get anyone and everyone into this war on their side since day three, (on day one and two they were winning so thought they could go alone!)
Eponllyn is unrecogniseable lately tbh. Its sad to think they managed to relocate and grow but have now fallen to the state where they feel they need to become just another part of Sirion's northern block. It isn't a surprising situation, they have had hard times, but I am genuinely sad to see one of the few 'old' realms I would have described as politically fairly independent now sitting in a situation where they feel unable to be so any more.
