Has Halfdan fallen out with brother Harald?

Does there really need to be one? He gave his reasoning to Bjorn a while back why he chose to go with him instead of stick by his brother.

I agree there hasn't the same level of foreshadowing like with Rolo where we'd see him jealously brooding over his brother's rise that made it appear betraying Ragnar was just a matter of time.

But by now sibling rivalries and backstabbing have become such a central theme of the show that I think it's subtlely implied Halfdan would rather wage battle against his brother to prevent being forever eclipsed by him should he become King of Norway. He also expressed to Lagertha that he feels loyalty to Bjorn for saving his life.

It's hard to know for sure whether Halfdan really feels this way or he's feigning fealty. But so far at least, Halfdan seems like a fairly simple guy who just goes with the flow. If he's faking it, I'd think he'd be more likely motivated out of concerns for self preservation and convenience than ambition or opportunism.

After watching the latest installment it looks like Hirst is portraying Halfdan's motives are sincere, as he defends his decision to go against Harald to his face because Bjorn had saved his life.

We hadn't seen enough of Harald and Halfdan's relationship prior but this rationale forces us to a couple hard conclusions. During all their time together during Harald's rise, in battle and elsewhere, never had Harald saved Halfdan's life or he would have said so when Halfdan twice raised the objection as his reason for his loyalty to Bjorn.

But you'll recall there was that time Halfdan saved Harald's life when the woman whose husband Harald had killed sought revenge. On some level, Halfdan must have felt it was a one sided relationship where his looking out for his brother Harald wasn't reciprocated. Meanwhile, Harald got all the glory. Implied is that in their short time together, Bjorn treated Halfdan more like a brother than Harald ever did.

So ok, I can sort of buy this even though I'd tell Michael Hirst that we never saw a hint of Halfdan feeling this way toward Harald until now. Maybe a tiny bit of foreshadowing would have made it more believable.

Far less believable in my opinion was Hvitserk's reasoning for staying to fight alongside Ivar. It's clear Ivar doesn't view or treat Hvitserk as an equal and at times treats him like absolute shit, even though Hvitserk admitted to Ivar his original reason for siding with him was he felt Ubbe looked down on him. Well guess what chump? Ivar not only looks down on you, he treats you an order of magnitude more disrespectfully than Ubbe ever did, and yet you stick by him?

I didn't find that believable at all.