Twelve stuntmen were set on fire as the History drama builds a 13,800-square-foot set for the famed historical battle.

In any given episode of History's Vikings, plenty goes into making the production as visceral and authentic as possible to the time period in which the Norsemen pillaged and plundered. In any given scene, there are at least 200 animal bones lying around. Each hair extension is made from real human hair. All garments take a minimum of two people and two weeks to create. It requires 20 people to move one of the longboats created for the series. Each battle scene is choreographed to perfection, and CGI is used minimally in the final scenes.

Thursday's epic "To the Gates!" episode is poised to see the drama up its game when Ragnar (Travis Fimmel) leads the raid against Paris, re-creating a famous historical battle with a huge fight scene — fire and all.

"We wanted to go to a new world. In terms of Viking society and where we've gone in the show, it's gotten bigger and more ambitious," showrunner Michael Hirst tells The Hollywood Reporter. "We have these wonderful guys who choreographed the battles. They had hundreds and hundreds of extras. We had loads of stunt guys and women. We do use CGI, but as little as possible. Our guys really fight."

Here THR breaks down by the numbers, exactly what went into filming the episode by the numbers:

In most shots, 12 stuntmen on fire when the towers are set ablaze. As a safety precaution, 150 gallons of protective fire gel were used.

A total of 206 stuntmen were hired to work on "To the Gates!" — and at least 500 stunt boxes were crushed.

There were 86 high falls from walls and towers into water and box rigs.

A 4,800-square-foot set was built to re-create the interior of the Paris Cathedral and Palace. The wall ramparts came in at 1,000 square feet.

Outside, the Parisian street and entrance to the Tower and Bridge totaled 8,000 square feet of space. That brings the new sets to a whopping total of 13,800 square feet.

The episode required two storyboard artists, 18 storyboards and 422 slides. Meanwhile, 59 concept drawings were drafted for Paris alone.

There were 1,100 flagstones used to construct the floor of the Paris Cathedral — and it took 200 liters of paint to create the marble. A total of 3,700 pieces of marble were fitted.

It took 150 candles to light the cathedral, and 450 replacement candles to keep them lit for one day of shooting.

An astounding 2,000 iron studs were used on the cladding of exterior Paris, while 176 panes of glass were fitted into the new exterior and interior sets.

In total, three siege towers were constructed for "To the Gates!" They were then replicated to produce more than 40 siege towers on screen.

While the entire third season of Vikings featured a total of 5,000 extras, this specific episode required 500 alone.

One new Viking boat was constructed for season three to accompany the three preexisting boats. The four boats were then digitally replicated to appear as a fleet of more than 100 Viking ships descending upon Paris.

"To the Gates!" airs Thursday, April 9 at 10 p.m. on History. Do you think the Paris battle will be the show's most epic to-date? Sound off in the comments below.

Twitter: @amber_dowling