'Vikings' season 5 spoilers: Series creator hints conflict among Ragnar's sons; Bishop Heahmund becomes Ivar's new rival

A major conflict between Ragnar's sons erupts when the hit History drama "Vikings" returns for season 5.

Season 4 left off with the sons of Ragnar being united by a sole purpose: avenging their father's death. Because of their different personalities, Ragnar's sons had different opinions on what they should do next — return to raiding, sail to other areas, or just stay in East Anglia. At the end of the hour, Ivar (Alex Høgh) threw an axe towards his brother Sigurd (David Lindström), killing him instantly. The episode also featured the arrival of Bishop Heahmund (Jonathan Rhys Meyers), which sets the stage for his large role in the next installment.

Series creator Michael Hirst recently caught up with Variety, and he revealed that season 5 will kick off with the fallout from Sigurd's unexpected death. While Ragnar's sons bury their brother, Ivar gets emotional and claims he never meant to kill Sigurd. The story takes a turn for the worse when the murder of Sigurd splits the brothers and forces them to reside in different camps.

"A large part of the next season will be about, will it be like this great Roman conflict after Caesar's death, the great Roman civil wars with Brutus and Cassius and Octavian? These people are playing for possession of the known world. It's not like a little local fight — these are huge territories," Hirst explained. "The Great Army has conquered a huge part of England. How do we behave now? That's what Season 5 opens with," he added.

Hirst also confirmed that they are already deep into the production of the 20-episode fifth season. He shared that while searching for new characters from history books, one interesting character jumped out at him in particular: Bishop Heahmund. "He's a man of Wessex, and he's gonna come in as a worthy opponent to Ivar," Hirst continued. "His whole life is about deeply passionate commitments," he went on to say.

History has yet to announce an official release date for the fifth season of "Vikings."