How to address Medieval Royalty and Nobility?

I know this is an in-depth question, but I could really use the answers. I always pick a best answer! Can anyone tell me how one would have addressed the following people in medieval times? Also, what are the differences in rank? Kings, Queens, and Princes and Princesses are obvious, but what status does one hold... show more I know this is an in-depth question, but I could really use the answers. I always pick a best answer!
Can anyone tell me how one would have addressed the following people in medieval times? Also, what are the differences in rank? Kings, Queens, and Princes and Princesses are obvious, but what status does one hold as a duke, count, etc...?

I have searched for the answers, but I keep getting varied results.

King
Queen
Prince (Heir)
Prince (Not an heir)
Princess
Duke
Duchess
Marquess
Marchioness
Earl
Countess
Viscount
Visnountess
Baron
Baroness
Knight
Peeress
Update: Wow, so much information! This is all great, and very helpful. I'm sorting through everything right now and seeing what fits with what I need.

Also, I should have stated that this was for English nobility, though the contributions for other countries have been helpful, too. :)
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