For the earthy, gritty and grimy “The Promised Land,” Denmark’s internationally heralded native son Mads Mikkelsen triumphs on this trip back to his Danish roots.

A true story, Mikkelsen’s Captain Ludvig Kahlen in 1755 has returned to Denmark after service in the German army. With a meager pension, he petitions his king to cultivate a barren piece of land. If he succeeds as a farmer, he is given a title.

Ludvig soon learns how incredibly difficult it is to grow something as simple as a potato, especially when sabotaged by the local landowner.

With deep roots in historical reality, “Land” chronicles the tragedy, obsession, romance and scheming that define the Captain’s struggles.

This captain, driven and ambitious, serves as a 10-years-later reunion for Mikkelsen with Nicolaj Arcel, his director on the Danish Oscar-nominated “A Royal Affair.”

“After ‘A Royal Affair’ we went back to the 1700s but this was so different,” the actor, 58, explained in a post-screening discussion with Arcel. “Because it’s all about nature and roughness and the elements.

“Shooting the movie, for the first time in my life I was actually able to shoot the picture where it happened: A protected piece of heath where Ludvig had actually built his house 300-plus years ago. We built his house on that spot. That was magical because we knew, ‘They had been here!’ It never happens – and probably will never happen for me again.”

As “Promised Land” ends, the dour, tightly enclosed man we first met has slowly become someone very different.

“In a very poetic way, he’s a changed man when it’s over – and yet you hardly see when it happens,” Mikkelsen said. “Here is a man who so desperately wants to be part of something – the Royal court — that he hates. It’s obviously a story about a man growing into being a human being.”

“When you try to change a character in a film,” the director allowed, “you are tempted to do this ‘One Big Thing’ that happens — and then he or she changes. We tried to not do that at all.

“If Mads hadn’t played this character I would have been too afraid to do it. Because it’s the nuances that make it work. That’s what makes us feel he’s a changed man — without any big scenes that tell us.”

“To do that, you have to have a director who lets the camera linger,” Mikkelsen said. “So you can see what’s inside. Because something is going on with the character — it’s bubbling. But it’s not coming out yet.”

“The Promised Land” is in theaters Feb. 2