On a field in England, the sons of Ragnar met Aethelwulfs army.
In Kattegat, Lagertha struggled to defend her city against a violent coup.
(Read the full recap here.)

Credit: History Channel
ENTERTAINMENT WEEKLY: There were two major battles in this episode.
Can you talk about what kind of preparation you do when youre constructing the narrative of sequences like that?
Do you read up on your military history?
MICHAEL HIRST:I think weve made the point right from the beginning to do each battle differently.
Im not a military historian as such, but I am interested in the history of warfare.
I can dive into historical books of any period and any culture.
Some battles [on the show], to tell you the truth, were inspired by Japanese warfare.
He is going to approach warfare in a different way.
Hes appreciated that the scale has gone up now.
The armies are bigger, the possibilities are bigger.
Were beginning to see something change in the show.
you’re able to expect [different] kinds of warfare, not just the shield wall.
I watched them shooting that big battle, and it was incredible.
There were just hundreds and hundreds of warriors.
People werethrowingthemselves into the battle, horses running at each other.
Ill tell you a story.
I said, Okay, but I want to be the lowest of the low.
Theres a certain day when Catholics used to crawl to the cross.
We were shooting the scene.
I said, Ill be a peasant.
I did this with all the Irish extras and kissed the cross very devoutly.
I had to get on a plane to the States, so I had an eyepatch.
I was just being punished for my hubris!
And, on top of it, they never used me in the scene!
Im not tempting fate.
What is Floki feeling in that scene?
Floki never wanted Helge to take the child away from her culture.
Floki still cannot come to terms with that act.
By his own lights, hes incredibly moral.
He thinks its wrong.
He feels for this girl, and its breaking the relationship with Helge.
As he says, very honestly, I dont know what to do.
He has to hand her back to someone he knows she hates.
One could sense an unhappy ending.
There doesnt seem to be any way of avoiding it.
Theres a tragedy waiting to happen.
Ivar tells his brothers that he considers himself the true heir to Ragnar Lothbrok.
The sons of Ragnar are all united now, but they are ambitious men in an ambitious society.
you’ve got the option to already sense the inherent tensions between them.
They are only holding together because they have this joint cause.
They are all committed to the act of revenge.
Ivardoesthink hes the true heir.
This is a society fueled by the need for fame.
We know theyre gonna be at each others throats.
After the battle of Kattegat, we saw that Torvi was lying dead amidst the mayhem.
You think shes dead, do you?
Yes…you mean she isnt?
You may be wrong!
I do take your main point.
A lot of thought does go into when a major character dies.
He kept looking around to see if I was coming!