Christianity vs Islam in feudal europe questions: How did the religions interact?

Did they exist peacefully or suffer from conflicts? What was the cause and effect of interactions between the religions?

Did cultural diffusion influence the different religions? If so, how? If not, why not?

What is the relationship between these two religions in the world today? Is there conflict, crossover, peace?

Can someone give me reliable resources for these questions? I can't find any that fit the criteria for using as resources in an assignment