When thinking about modern kings and queens, Elizabeth II is the first that comes to mind. But the longest-reigning monarch is hardly the only one out there in the world—in fact, there are 29 modern monarchies, reigning over 40 countries. Some, like King Salam bin Abdulaziz Al Saud rule absolutely, while others, such as King Willem-Alexander of the Netherlands, serve more as ambassadors for their country's governments.

Others still aren't even kings or queens, but rather princes reigning over principalities, like Albert II of Monaco or grand dukes over dukedoms, like the one in Luxembourg.

Read on for all the current sovereign heads of state, from the King of Bahrain to the Pope.