After the revenge for Ragnar's death, "Vikings" season 5 will see the fallout of the Lothbrock brothers. The new trailer for the upcoming season teases the clash between Bjorn, Ivar, Ubbe and Hvitserk. Meanwhile, it is expected that bishop Heahmund will take the center stage to antagonize the brothers.

The unity of the Lothbrock brothers for avenging their father in the season 4 finale was quite short-lived. After winning the battle in Wessex, Ragnar's sons had a conflict on what to do next. Bjorn (Alexander Ludwig) wanted to return to the Mediterranean. Ubbe (Jordan Patrick Smith), Hvitserk (Marco Islø), and Sigurd (David Lindström) want to honor their father's wish to build a farming community in Wessex.

But who would want to farm when they a great army at their disposal? Ivar (Alex Høgh Anderson) wanted to attack and raid new places. The debate turned sour and without thinking, Ivar axed Sigurd in the chest, immediately killing him. "Vikings" creator Michael Hirst teased what would unfold in "Viking" Season 5.

Lothbrock Brothers

In an interview with TV Line, Hirst revealed Ivar will regret killing Sigurd. He described the first scene in "Vikings" season 5, episode 1 of Ivar weeping during Sigurd's "Ivar is weeping and saying it wasn't his fault, that Sigurd had pushed him, that he loved him, he was his brother," Hirst said. "He regrets doing these things. He can't help himself."

However, this doesn't undo what's done. Sigurd's murder only demonstrates their brittle unity and Ivar's madness. He further revealed that two of his sons would push to pursue Ragnar's dream while Ivar will continue leading the army. "They're faced with the Great Heathen Army, and there are two kingdoms that have almost fallen to the Vikings - and that's only the start of it!" Hirst told Entertainment Weekly.

Hirst explained Ivar's character -- dangerous and mad. His brittle bone disease made him quick-tempered. He said killing Ivar proves nothing can stop him to do what he wants to do. He cannot be bounded by morals or human ethics. He added that he is a very sensitive man. As for the conflict between the Lothbrock brothers, he revealed it would soon "end up in a world war."

Saxons And Bishop Heahmund

The "Vikings" season 4 finale also introduces us to a new character that could stand up to the great Lothbrock family -- bishop Heahmund (Jonathan Rhys Meyers). He is no ordinary church leader. Well, that much was obvious with his unique introduction: sex and a bloodied sword.

Bishop Heahmund is a warrior bishop. In history, he was a precursor of the Knights of Templar. Aside from being a spiritual person, Hirst revealed that Heahmund is trained to fight. He went on to explain his character. It looks like we've got ourselves a very complicated character. Heahmund takes advantage of women especially those who looks up to him as a bishop then punishes himself later on.

Ecbert's brilliant decisions before his last breath will have a huge impact for the Vikings and Saxons. He wasn't King when he signed the land to the Vikings, he passed his throne to his son and let him escape. "Vikings" season 5 is already deep into production. It is expected to air later this year.