Throughout history, expanding territories and building empires have been the favorite pastimes of both sane and insane dreamers. Some of them were successful in achieving their goals, while most others failed miserably. Indeed, empires are rare commodities in world history. One thing to note about the great empires of yesteryear is that they usually lasted for a very long time, but often ended quite abruptly.
The Roman Empire
If greatness is measured by legacy and influence, the Roman Empire would undoubtedly be considered the greatest empire in history. The Romans left an undeletable stamp on world history. Roman philosophy and laws (which were highly influenced by the Greeks) helped formed the social thinking of western civilization. Contemporary culture, language, architecture, arts and systems of representative government are advanced versions of those of the Romans. Simply put, modern society would not be what it is today without the existence of the great Roman Empire.
The Chinese Empire
No empire lasted as long and was more influential than the Chinese Empire. At its peak, the Empire nearly encompassed the whole of Asia. What allowed the Chinese Empire to retain its power for more than a thousand years (and through many dynastic changes) was their clever approach to governing. The Chinese dominated their Asian neighbors not just by military might but also by exporting their culture to these countries.
Have you ever wondered by many Asian languages, particularly Korean and Japanese, share similarities with the Chinese language? Have you wondered why many pre-modern structures in Asia appear to be inspired by Chinese architecture? The Chinese also had their stamps on Asian cuisine, social philosophy, arts and music. Ironically, the great Chinese Empire fell to the nomadic Mongols, whom they deemed to be barbaric and uncultured, and subsequently to another nomadic group from Manchuria.
The Mongol Empire
If greatness is measured by scale, the Mongol Empire would be the definite candidate for the title of the greatest empire. At its peak, the Mongols were the masters of Eurasia whose territories encompassed most of Asia (including China), the Middle East (Persia), and Eastern Europe (Russia). Unfortunately, the Mongol Empire did not last very long.
Although the Mongols were impressive conquerors, they were inept administrators. There was no central authority as each territory was governed by a different khan, who paid deference to the Great Khan, but was not in total submission. Additionally, the Mongolian brutal and genocidal tactics in conquest led to deep hatred of them among the locals. The Mongols were eventually driven back to where they originally came -- the vast grasslands of Mongolia.
The Napoleonic Empire
The Napoleonic Empire is one of history’s greatest empires. Napoleon Bonaparte, the regime’s absolute ruler, managed to achieve the near impossible which was to dominate Europe at the height of its power. At the time, Europe was the world’s most influential continent enjoying some of the most powerful military might. The fact that Napoleon was able to keep such a monster in check for even a short period was an incredible feat -- one that would only be equaled some 150 years later by Hitler’s Third Reich.
British and French colonial empires
The British and French Empires were often mentioned in the same breath, because they were the dominant powers (as well as fierce rivals) in the age of imperialism. At the height of their power, the two reigned over a large swath of the world. The British Empire included the Indian states, the Oceania states, islands in the Americas and several African countries. The French Empire included most of Africa and southeastern Asia. Unlike the Roman Empire, these colonial empires left no notable legacy of development. Instead, they were responsible for the rise of nationalism in Africa and Asia. Many revolutionaries, who led revolts against colonial rule, became their country's national heroes. Ironically, many of these heroes (sans the justly revered Gandhi) went on to become ruthless dictators who oppressed their own people.