Ubbe was the most like Ragnar, just without the uncontrollable rage which made him even smarter. He had the rage but he always had full control of himself, able to think clearly in the worst and harshest situations. Out of all the brother Ubbe sealed his fathers dream by finally owning east anglia. He is very underrated. Him and Bjorn were almost unstoppable when they were together. If ivar had stayed loyal to his brothers they would have been unstoppable with all of that plus ivars mind and ability to make battle tactics. Plus hvitserk, an animal on the battlefield. They’d have taken all of England together.
