The first seasons of Vikings reminded me strongly of Sons of Anarchy. Not just because leading man Travis Fimmel bears an uncanny resemblance to Charlie Hunnam, but because of the shared themes of brotherhood, loyalty, and independence. Sons writer Kurt Sutter tried to make his show feel authentic by learning from and working with people involved in the world he was writing about. It’s of course quite different when you’re writing about people who lived over a thousand years ago, but nevertheless Vikings writer Michael Hirst has generally seemed concerned with making Vikings feel like a historically grounded and serious-minded drama. It was therefore regrettable to discover that this first half of Vikings’ fourth season reminded me of nothing other than Game of Thrones. I never cared for George Martin’s overrated fantasy series, but sadly Vikings’ showrunners seem to have decided that treacly pacing, betrayal, and incest are what the viewing public wants, because much of these episodes consist of just that.

Each season of Vikings has seen its scope expand, and by season four the action isn’t limited to the homelands of the Norse marauders: significant parts of the story are now set in England and France. They say success is a double-edged sword, and the critical and commercial success of Vikings means we now have 20-episode seasons, released in two parts. The beginning of season four sees the Vikings return home after a costly adventure to Paris; they won a military victory and acquired lots of treasure, but at the loss of many lives, and king Ragnar Lothbrok (Fimmel) is himself at death’s door. In his stead his son Bjorn Ironside is forced to make some executive decisions which prove that, well-intentioned and forceful though he is, he is no politician.

Much of the season sees the Vikings prepare for another attack on Paris. Irritatingly, once he recovers Ragnar continues to behave in the reckless manner that characterized him in season three, and he spends several episodes wrapped up in a quasi-romance with a Chinese slave who gets him addicted to opium. Otherwise the vikings mainly spin their wheels while waiting for Ragnar to give the order to attack Paris again. His relationship with Aslaug is increasingly one of mutual disdain, and Aslaug becomes more and more emotionally dependent on her crippled son, Ivar the Boneless. Aslaug also tries to repeat her dalliance with the mysterious Harbard. This mainly felt like an excuse to get more naked flesh on screen as Harbard shags his way through Kattegat while all the men are away in Paris.

At the end of season three, Ragnar’s unreliable brother Rollo was left behind in France in charge of the vikings who stayed behind. This has predictable consequences and Rollo is soon enmeshed in the French court. Most of the worst and most tiresome parts of the season happen in Paris, which plays host to the kind of political intriguing, backstabbing, incest and general depravity which one associates with the aristocracy. The situation in England is largely the same, the exception being that the charismatic King Ecbert (Linus Roache) invests the story with a sense of purpose and vision which is otherwise largely absent in these episodes.

I’m sorry to see the way Vikings go downhill like this. For some time I’ve been eagerly telling friends and family to watch this show, emphasizing that while it is enjoyable drama, it is also a thoughtful and responsible piece of historical fiction. In that regard the first couple of seasons felt like an antidote to the asinine titillation served up by Game of Thrones. It’s also strange that while much of the season meanders on with nothing much happening, the writers then decide to jump forward ten or more years at a stroke. Episode ten hints strongly that future episodes will revolve around Ragnar’s sons, and the writing team has a job on their hands to ensure a successful transition of the narrative from Ragnar to the next generation. At this point, as with Ragnar himself, I doubt they’re up to the job.