Here are some links to pages I enjoy going to and think you will too. Check it out, it is kind of funny. Rulers of the World gives a list of heads of state and government from all countries from about 1800. Valley of the Kings gives information on Ancient Egyptian Kings Royal History gives information on royals from around the world.
Royal Scandals show how kings and queens can make quite a mess of things.
Royalty in History is a page similar to the Mad Monarchs Series. It focuses on peculiar royals.