On DVD "Making Of" documentary of Pathfinder (2007), Producer Mike Medavoy specifically refers to the movie as a remake of Ofelas/Pathfinder (1987). The project was initiated, according to Medavoy, specifically as a remake of Ofelas, and that's how he approached the director, Marcus Nispel. Both men mention this, separately, in their respective interviews on the DVD of Pathfinder (2007). The 1987 movie deals with Vikings attacking the Sami minority of Scandinavia, in the 2007 version the underdogs are the Natives of America/Canada. Note that in Ofelas/Pathfinder (1987) the villians are not Vikings but Chuds, a different people.
both the ice scenes in Pathfinder and King Arthur are based on this Russian movie about a specific historical event
When the hero lures the vikings on an icy lake that cracks under their weight (the scene even shares an effect shot from King Arthur, of the ice breaking)
Poster on the cinema theatre marquee.