Lokking for a movie I watched years ago

I'm trying to identify a historical adventure film or series. Here are the key details I remember: The story centers around a young warrior who saves a woman from another tribe while hunting, rescuing her from a bear. The film involves several different tribes, who are facing a new threat: an invading army of foreign warriors, who resemble Mongol-like forces. The main tribe trys to make allys with the other tribes to face the threat. But there are also conflict between them. The younger son of the tribe leader plays a key role, and his older brother is killed (I think) during the story. Their mom also dies. A mute blacksmith is an important character in the village, and he cannot speak. Towards the end of the film, the main characters fight against the overwhelming invaders. The climax involves breaking a dam to release a flood that destroys the enemy forces. The mute blacksmith is the one who pulls the lever to break the dam. The enemies are ultimately defeated by the flood, and the leader of the invading army is seen standing on a rock in the water at the end.If anyone knows the name of this film, please let me know!