Alex Hogh Andersen in Vikings Season 4

Vikings season 4 will certainly go down as a season marked by tremendous change. Not only because it was comprised of a super-sized 20-episode run that stretched from 2016 to 2017, but also because, despite allusions to being an ensemble, it killed off the series' ostensible protagonist in Ragnar Lothbrok, with several weeks still left to go. Though not necessarily a surprise, the move was a game-changer, shifting the narrative focus from the increasingly world-weary Viking leader to his now-grown sons and their quest for vengeance. The question became: After nearly four seasons of following in Ragnar's bloody footsteps, could the series remain as captivating and entertaining as it has been?

As it turns out, those last few weeks between Ragnar's death and the season 4 finale, 'The Reckoning', worked as a sort of proof of concept that Vikings could offer more than one compelling reason to continue watching its post-Ragnar narrative. For one thing, although he's no longer on the series the Ragnar's presence (and that of Travis Fimmel) is still felt in every action of his sons – especially Ivar, whose ambition is mixed with a similar otherworldly mania that teeters on the brink of psychopathy at times. Ivar's self-proclaimed position as the co-head of the Great Heathen Army cements his role as successor to his father and potential equal to (or nemesis of) his half-brother Bjorn. Such interpersonal intrigue is a familiar part of the show's nature, a specialty of creator and writer Michael Hirst, who never met a character whose bald-faced desire for greatness he couldn't translate into television drama.

Such machinations are often the engine that drives the plot, and while the latter half of season 4 has carried them in like pillagers on longships, they are largely asked to take a backseat to the visceral indulgences of bloody warfare and the invasion of the Great Heathen Army. After giving King Aelle the ol' Blood Eagle late in the penultimate episode, 'On the Eve', Vikings turned its attention to Ivar's gift of military strategy, decimating Aethelwulf's army before ending the episode on a cliffhanger.

Vikings Season 4 Finale

Following the episode, Hirst spoke about his plans to introduce a new character a "warrior bishop" by the name of Bishop Heahmund, played by Jonathan Rhys Meyers, in the season finale. While Meyers' inclusion isn't so much a surprise – he and Hirst worked together for four seasons on Showtime's The Tudors – the idea of a new character being brought in for the finale, presumably one on which future narratives will rely, is almost as bold a step forward as dumping Ragnar into a pit of snakes.

'The Reckoning' was in large part an acknowledgement of Ragnar's legacy. Regardless the difference in their respective bloodlusts, Bjorn, Ivar, Hvitserk, Ubbe, and Sigurd were all in England to avenge their father's death. Yet even as the episode began with a prolonged and technically impressive battle against what remained of Aethelwulf's army, there came to be a sense of division between the brothers – at least in terms of what they were hoping to achieve. Hirst establishes two distinct points of view: Bjorn and Ivar, and the three remaining brothers are largely left to react to the decisions and actions carried out by their more aggressive siblings but it also makes the structure of the narrative more manageable, especially when dealing with Braveheart-sized battle sequences and their aftermath.

It's surprising, then, that while the battle that kicks off the episode is huge – both in terms of the loss of life and in how it demonstrates what a television series is given the freedom to do in this day and age of Peak TV – the rest of the hour is more or less confined to one location and one group of characters. Once Aethelwulf is given the crown, he, Judith, and the children are off, leaving Ecbert and one resilient Bishop to await the Heathen Army's arrival. Paring down the scale of the hour gives an additional weightiness to what unfolds on a much smaller, character level.

Bishop Heahmund officiates a burial ceremony in Vikings

Hirst is not shy when it comes to bringing about sweeping change, and that often means he's not sentimental about moving characters around or out of the picture all together. 'The Reckoning' moves in a flurry of critical character beats, starting with the death of Helga by the child she'd attempted to adopt following the sacking of a Muslim city in the Mediterranean. Helga's death is perhaps the most surprising of the hour, if only because Tanaruz didn't appear to be much of a physical threat, let alone capable of a hasty murder-suicide. The result leaves Floki's future in question, as he choses to walk the earth following a season filled with grief. Having already lost his daughter and Ragnar, the loss of Helga is seemingly too much to bear. Floki has always been an interesting case, ruled by his emotions more so than almost any other character, so his decision to peace out just when it seemed his brethren were on the verge of achieving Ragnar's dream is in keeping with how the character has functioned in the past. It seems unlikely that this will be the end of Floki, though, given how integral to the series he's been. Though this does set up the possibility of a grand return in season 5.

The rest of the episode is devoted to the death of King Ecbert, and his betrayal of Bjorn and the other Vikings, granting them a significant stretch of land after his kingly powers have already been renounced and passed to his son. Ecbert's end is inevitable considering the role he played in Ragnar's death and it, along with the late introduction of Meyers as Bishop Heahmund is perhaps the most significant event moving forward. Though he was no longer king and his death was by his own (forced) hand, the response it will trigger will likely be tremendous in terms of its impact on the invading Vikings.

With Bjorn in full snowbird mode, that leaves Ivar as the driver's seat, so to speak. His desire to keep raiding makes him a threat not only to the people whose homeland he's invading, but for those who stick around as well. There isn't much more Hirst can do to demonstrate Ivar's character than by having him murder his brother in a fit of rage. The moment makes its point, and though there's a brief look of panic and maybe even regret on his face as Sigurd pulls the ax from his belly, Hirst is clearly taking Ivar down a dark path.

In all, Vikings season 4 made for a terrific season that made the most of its super-sized episode count and delivered a stunning end to several longstanding storylines, while also paving the way for some compelling new ones as well.

Next: Vikings: Where Will The Series Go After A Game-Changing Episode?

Vikings will continue with a 20-episode season 5 on History later this year.