http://revach.net/article.php?id=3504

Section: Revach   Category: Lists
4 Men Who Ruled Over The Entire World & 4 Who Didn't
Hashem is the ruler of the world.  However he has given man power to conquer and rule over territories and people.  Surely those who ruled over the world were appointed by Hashem for this task for a reason.  The gemara (Megila 11b) lists a number of people who ruled over the entire world and a number whose conquest fell short.  To see the Revach List click here.