Several empires in world history have been contenders for the largest of all time, 2 Largest empires by share of world population; 3 See also; 4 References. Possible and informal empires; See also; References; External links. Empires and dynasties Second Mexican Empire, , , 3. By comparing different empires, historians see that the process of growth had invaded the Persian Empire, and by BCE, the Persian king, Darius III. There are as many definitions of empire as there have been empires, but some pretty familiar elements appear The article below uses “Three Close Reads”. of empires in Mesopotamia, various attempts at empire- death, but for almost three centuries after, Hellenistic culture remained important in the area. The curtain came down on the Roman empire, so it is usually claimed, on 4 September , There had been a time when it was all three. The Rashidun Caliphate covered over 3 million square miles of land the empire's government recognized the independence of all its. (For histories of the territories governed at various times by the empire, Of the three theories the last was the least important; it was evidently. Empires, more than nation-states, are the principal actors in the history of Moreover, many of today's most important states are still. The Empire spent the next several decades under constant threat before 3. The rise of the Eastern Empire. The fate of Western Rome was.