He married Diana because she was the only virgin he could find that would marry him. I NEVER EVER thought they loved each other.
It was sort of a traditional arranged marriage. Diana’s grandmother was a lady in waiting to Charles’ grandmother. Her grandmother pushed the idea, and his liked it.
She was very high aristocracy, and she was young and no one was talking about any past sexual history. They probably gave Charles several suggestions of appropriate brides, and he picked her.