Rooster attacking my Hen

[familyof4]

Thank you all so much for your help!! It just seemed so strange that all of a sudden he started picking on her, he was literally on her pecking and scratching her to the point of her bleeding. I ran down there and he jumped off, but now I am so scard he will do it again. The three of them have lived happily together for over a year since my other 2 hens passed away. There has never been a problem.