These 5 Great Empires Changed World History Forever There are some empires that were simply so powerful, large, and influential over the grand sweep of history that they deserve to be called the greatest, no matter the criteria. Here's What You Need to Remember: For all these reasons, America has a long future ahead of it as a great power. Yet, America also needs to keep in mind the faults of previous empires if it is not to repeat them. Of all the empires that arose and thrived on the face of this earth, which were the five most powerful? And how is it even possible to select five empires from among the hundreds that have flourished over the past five thousand years? Truth be told, any formulation of the “five most powerful empires” will always be subjective, because all empires were glorious and influential in their own ways.