I guess it's quite easy to be independent in a realm with more than the triple of nobles, and a very good proportion of them with quite a lot of experience and wealth to sustain a large troop. I've been playing for little time, and if Aurvandil had hard times, it had to be a long time ago.
When you've got the guarantee of a huge army at your back, you don't have to do politics. You just have to decide which could be a good pretext to invade a region whether it's an active part of an enemy realm, or it has gone rogue for some reason. I can understand it of course, it has to be just awesome. Moreover, it's interesting to see you talk about "being screwed" by constant changes in the diplomatic relations with other realms. Does it really affect Aurvandilians somehow? A king who can move at least 20 nobles whenever he wants, each one of them with at least 700CS has to be difficult to screw, doesn't he?
So you think Barcans are peasants of the Zuma. Yeah, it would be probably much nicer just to blow us from the map to put a good bunch of Fiorenze or just expand your realm; it is surprising to see it bothers you.
Justify your invasions as you like, but please don't show Aurvandil as a victim of the inconsistent politics of other realms. For your fortune, I think you can't be a victim of anyone, and you will be a probable choice for new members (everybody like to fight battles with an overwhelming numeric superiority, right?).
The irony of you arguing Aurvandil hasn't had a hard time in a long is overpowering. Considering Evanburg, Gallaecia, Celtiberia, Zerujil and Candiels all recently revolted, well the Candiels revolt was put down. As it turns out, Aurvandil is surprisingly easy to screw into ruin just by war declarations which is the state we're currently in internally, we have the best army on Dwilight and quite arguably the game, but out enemies found a way to make that irrelevant and force us to bend over.
And I rather like having Barca on our border, it's like having a desert, it's easy to ignore. Which suits Aurvandil just fine, so long as Barca doesn't make us notice them, we won't and we'll leave them be.
And your argument of our wealth and power makes it impossible for us to be victimised in anyway is just silly.
