Why is there no King at the wedding?

OK, I’ll admit it. I watched about 15 minutes of the wedding. (There! I said it!) I even went to the Royal Family’s website and spent some time looking at the family tree so I could understand who’s related to whom and did what to whomever.
At the top, I see the Queen and Prince but no King.
I’m sure there must be a back story to this but I don’t see it. Will there ever be a King?