Vikings has the best battles on network television. So of course, Inverse had to talk to John McKenna, the show’s official armorer. McKenna has also worked as an armorer on Ripper Street, King Arthur, The Lobster, Six Shooter, The Wind That Shakes The Barley, and more.

So what exactly does your job involve?

I supply and come up with all the weapons that are used by the cast and background on the Vikings TV series.

Do you personalize the weapons for each character?

Yes, each of the main principles have a set of dedicated weapons. A first set and a set of doubles so we can shoot with them and a double at the same time. Each individual pretty much whatever the stunt guys decide are best suited for them. There’s nothing that the cast won’t rise to! They always love a challenge. Just about everybody from Alexander, Lagertha: Everybody just gets right into it.

Which character is your favorite to arm?

It’s great to work with Travis [Fimmel] and all of the cast. Looking at some of the fighting routines they have done. I suppose Clive [Standen], because his fighting routines have always been heavy-handed. He became the ax-man. The berserker. He goes to Paris, and he seems to change his style of fighting, but he’s still a viking at heart. He’s just one guy you do not want to meet on the battlefield.

Before this show, were you familiar with Viking weapons? Or did you need to do research?

As an armorer for 33 years, I have worked in many shows: historical, contemporary, and everything in between. But when you get a job like Vikings you really don’t want to get it wrong. There’s a lot of research done at the start and, then, the show progresses and you introduce different weapons. As a reference, you tend to look back and research to see what’s out there. Then you get a little creative around that.

What do you mean by “creative”?

The items that might have been correct at the period would not necessarily be pretty. The design department or art department or costume might say, “Can we glamorize that?” because somebody is more important or regal. So you might have to adjust and take something that might have been something simple like a knife with a bone handle and try to embellish it, just to make it special and stand out for an individual.

What’s the most surprising thing you’ve learned over the course of your research?

The use of the ax is extraordinary. It went from something like a simple farm tool that would be used for, perhaps, boat building, or their connection with timber and trees. The variety of axes that they used from small to slightly mid-sized, Danish axes, they had a love affair with this weapon. When you’re making it constantly for the show and trying to alter it slightly, it is an interesting weapon. Some of the fight routines as a result of using these weapons are extraordinary.

Since you’ve been in the business 33 years, have you seen it change much?

Since 2003 — when I did King Arthur — a lot of these sword blades used back in those days were made from aluminum, aircraft grade, and would have been substantially heavier. But within the last four or five years the industry standard has moved to bamboo. This is the material that most stunt coordinators wish their cast to work with. I have to agree. Probably 50 years ago, sword blades on movies — while blunted — would be made from steel. I suppose in the last 20 years that changed to many a blade. That is heavy in its own right but with bamboo, cast members can literally work away all day on their routines without it tiring them out.

What’s been most challenging about this current season of *Vikings?

As the Vikings started to expand the horizons — and they decided after sailing to England and then sailing to Francia — the challenge then is coming up with something different with the French. We collaborated with the art department and the designer wanted a new look so we had to come up with something. The crossbow is what appeared for the French. They were a more sophisticated people. So he wanted something different for them. A great deal of interest in season 3 is the siege of Paris.

As the show has gone on and the battles have grown in scope, does it take longer to prepare the weapons now?

It’s kind of extraordinary. We started with about 30 Vikings and 40 Saxons. We had two boats. I was looking last week, at one of the sets up on Kattegat here in the studio, and there’s 10 boats in the water. There are five times more warriors. When the Vikings go out to show in strength now there’s about 250 vikings. The show grows each year. Four to five weeks of prep is what we get at the start of the shows, between the downtime from one season to the next. And then you have to look and rebuild the old stock of what you had from the previous season.

Any good battles on the horizon for Season 4?

Oh yeah, absolutely. There are some fantastic things that are coming up. I mean, this is 20 episodes, the first time we’ve gone down that route. There are some absolutely fantastic set pieces to be seen.

Vikings airs Thursday nights on the History Channel. Forged in Fire airs Tuesday with its “Viking Sword” episode.