Actor George Blagden is likely to portray the spirit of Anglo Saxon monk Athelstan when the show returns on History Channel with season 4 in 2016.
Ragnar Lothbrok (Travis Fimmel) was deeply affected by the death of his close friend, but the monk's spirit will not have a great impact on the Viking leader, according to creator Michael Hirst.
"George would be hovering around the whole time. In reality and in spirit Athelstan continues to exert a big influence not necessarily on Ragnar, but on King Eckbert (Linus Roache) in Wessex and on Athelstan's son Alfred," he said.
The showrunner even stated that the death will play "a big role in the lives of the living" and Floki (Gustaf Skarsgård) will have to pay for being the cause of Athelstan's demise.
However, Lothbrok will be more concerned about his sons, including Bjorn Ironside (Alexander Ludwig) and Ivar the Boneless, than the monk in "Vikings" season 4 as he fears that they could be more famous than him.
While revealing that the children of Fimmel's character will play bigger roles in the story, Hirst mentioned that some of them will become more famous than their father.
"This has never been the Ragnar Lothbrokshow, this is a show about Vikings. And again historically speaking, a couple of Ragnar's sons did become more famous than he was. I'm thinking particularly of Bjorn and the wonderfully named Ivor the Boneless. Ivor's story is a crucial and amazing part of season four," The Hollywood Reporter quoted him as saying.
Meanwhile, actor Clive Standen, who portrays Lothbrok's brother Rollo in the history series, teased a few epic fight sequences of the fourth season.
"Our great writer Michael Hirst has written these amazing episodes for the [second third of season 4] and we've got boat battles, capsizing boats and Vikings fighting on the sea, which is what they did fantastically well and we've never done it so far," he told Nerdgeist.
So, fans of the popular drama series can except some exciting battle scenes between Rollo and his brother in "Vikings" season 4.