Most of the main characters in Vikings were known for making questionable decisions. Ragnar and Alsaug's first son, Ubbe Ragnarsson, was no exception. Ubbe was impulsive, a trait that made him act recklessly, resulting in consequences for both the character and those associated with him.
Fans questioned Ubbe's decision-making when he attacked Lagertha in the Great Hall without a plan and when he accepted Othere as an ally. However, those were only his minor missteps. A number of times on the show, Ubbe's wisdom totally departed him, causing viewers to hold an everlasting grudge against him.
During Ubbe's time as the temporary law-giver of Kattegat, Gunnhild had a dream of a village being burnt. She strongly believed it was Lagertha's village but Ubbe dismissed her. Days later, White Hair and his men invaded Lagertha's village. Consequently, Lagertha was badly wounded and was unable to defend herself when Hvitserk accidentally killed her.
Ubbe's failure to take Gunnhild seriously is unforgivable as it led to the death of one of the show's best characters. Gunnhild was more than willing to go help and if it were not for Ubbe's nonchalance and arrogance at the time, lives would have been saved. Ubbe's failure to adopt preventive measures was a hint as to why Ubbe never became a revered ruler like Bjorn and Ivar.
Eager to claim the lands that King Ecbert had signed over to Ragnar, Ubbe proposed a truce with the Saxons. Aethelwulf accepted but Heahmund humiliated Ubbe and Hvitserk by beating them up and killing off their bodyguards. The humiliation meant Ubbe and Hvitserk could no longer continue to lead the Great Heathen Army, so Ivar took over.
Ubbe's preference for peace over war led to the rise of one of the greatest despots on the show. The people of Kattegat would have been spared of Ivar's tyrannical rule if Ubbe had refrained from being too friendly to the Saxons. He had no reason to seek peace with them since he had the upper hand. The Great Heathen Army had already defeated the Saxons when they entered through the old Roman walls.
As a child, Ubbe and his brother Hvitserk were briefly left under Siggy's care around the same time Aslaug was away cheating on Ragnar. They proceeded to play on top of a frozen lake, despite calls for them not to do so. As expected, the thin ice gave in. Siggy's attempts to save them led to one of the most unexpected deaths in Vikings.
Siggy's death was hard for viewers to take because she had previously lost her daughter Thyri and her husband Earl Haraldson. She had a promising future as the show constantly hinted at a strong romance with Rollo. Siggy was generally portrayed as a strong woman too who was against injustices. This was best seen when she campaigned against her daughter being sold off in marriage to the elderly Earl Bjarni. If Ubbe hadn't been stubborn, Siggy would still be alive.
Ubbe fell in love with Aslaug's slave Margrethe and married her. This was a bad idea because she had her sights on becoming Queen. She pushed Ubbe to kill Bjorn and beray Lagertha so that he would be king.
Ubbe's failure to see the red flags that were all over Margrethe pointed to his glaring lack of awareness. That Margrethe had been okay with sleeping with all of Ragnar's sons and even being shared while married was problematic in itself. After he began seeing Torvi, Ubbe tried to justify his infidelity by claiming Margrethe was jealous and unfit to be a wife. He should have refrained from marrying her in the first place instead of cheating on her.
Iceland was among the 11 countries the main characters explored and it featured heavily in the storyline. The moment Kjetill Flatnose told him about the largely unoccupied land, Ubbe didn't think twice about going. His failure to do due diligence would come to haunt him as he and Torvi went through many horrors, almost dying in the process.
Ubbe should have known better than to follow Flatnose, who was known to be a self-centered and heartless man. His decision to leave was also threatened his family's stability and his own future. By staying, he would have continued being Born's trusted advisor. By leaving, he was not only putting himself at risk but also Torvi and their unborn child.
As Bjorn was leaving to go help Harald, he put Ubbe in charge of Kattegat because Hvitserk was too sick and intoxicated to be acting King. Still, Ubbe found it wise to appoint Hvitserk as the leader of the Silk Road traders. Hvitserk didn't show up to lead the men and almost jeopardized the whole trade process.
This was yet another example of Ubbe's poor leadership skills. He had plenty of competent men that would have taken the role but chose to base his selection process on nepotism rather than merit. Ubbe choosing to push responsibility on his brother at his lowest moment also soiled their brotherly relationship. After Hvitserk's failure to apply himself, he and Ubbe would never be close again.
Ragnar was received coldly when he reappeared after 10 years. He had a plan to go to England but Hvitserk and Bjorn strongly declined, opting to make a voyage to the Mediterranean. On his part, Ubbe opted to stay in Kattegat.
Though refusing to assist Ragnar was a collective decision that the sons made out of bitterness, Ubbe had the freedom to make up his mind. He clearly loved his father, evident from how he refused to fight him for the throne. If he had helped Ragnar, he just might have prevented the former Earl from going on a downward spiral and losing all hope in life, leading him to surrender to Aelle and Ecbert.
Upon realizing how desperate Ubbe was to get the lands in East Anglia, Alfred ordered him to get baptized and prove his loyalty to him. Just like Rollo had done before, Ubbe agreed to be baptized together with Torvi.
Ubbe's baptism means he might not among the Vikings characters who are currently in Valhalla. Christians or members of any other religion cannot enter the Norse paradise. Ubbe's pact with Alfred didn't bring the older Ragnar son any joy either since it was marred with challenges. He faced opposition from Frodo while trying to lead Alfred's army. His efforts to get his own people to settle in East Anglia didn't go well either. Wallowing in despair, he was forced to go back to Kattegat before journeying to Iceland.