What is the name of this Sci-Fi movie?

It's about some man from another planet. He is a normal human but his kind are very advanced and have a bunch of powerful technology. I didn't see the beginning but somehow he crash lands on earth. Here on earth it's the medieval ages. He eventually finds this town they call him outsider all the time and he falls in love with one of the women there. Supposedly he accidentally brought some kind of beast-monster to earth and it had babies in a cave or something and he leads the people in a fight against them. In the end he decides to stay on earth and marry the girl. Any ideas of what the name could be? I wanna watch the whole thing.