He's always been ambitious but it's simply pragmatic alliances and politics now, he's getting on.
On the Rollo Lagatha bit, I just checked and
series one, episode one...
Meanwhile, back at home, Rollo makes unwelcome advances on Lagertha. I can't rememebr the precise details, I'd have to watch again, but the suggestion he could be the father instead of Ragnar is not unreasonable.