A picture of the production set of "Vikings" TV series by History Channel. Vikings/ Facebook

A new video about “Vikings” TV series has been released online. It traces the journey of the great king Ragnar Lothbrok (Travis Fimmel), also revealing his greatest fear. The story of the show has now focused on the sons of Ragnar, who will go on to do great things, too.

Series creator and writer Michael Hirst appeared in a video on Facebook to talk about the reported history on which the story of the show is based. The plot of the series at the moment revolves around Ragnar's sons. Hirst said that the sons went on to accomplish things that are just as grand, if not more, than what Ragnar achieved in his lifetime.

There have been reports, Hirst said, suggesting that Ragnar’s biggest fear was that his sons would one day do incredible things and become more famous than him. That fear is justified as the sons are capable leaders able to achieve great things at a young age.

Danielle Turner, author of “Change in Northern Winds: A Modern Review of the Viking Siege of Paris,” said that one of the contributing factors to Ragnar’s early demise is his jealousy towards the accomplishments of his offprings.

Apart from being the sons of Ragnar, another important reason for the boys' accomplishments is their mother. Alyssa Sutherland (Queen Aslaug) said in the video that Aslaug wanted to leave behind a legacy, making sure her children are the most famous of all of Vikings.

Meanwhile, a new teaser trailer of “Vikings” season 5 has been released online. The video (see below) teases the beginning of the end. Next season will deal with the full consequence of the death of Ragnar, which is something the Seer (John Kavanag) has perceived.

Credit: Vikings on HISTORY/ Twitter