What nation-state headed the most powerful contiguous world empire in human history?
Te question is so vague that it’s probbaly going to end up as a debate.
How do you define powerful? Powerul militarily? Powerful economically? Powerful culturally? Powerful compared to contemporary powers? Powerful in absolute terms.
In terms of absolute military power I guess one would have to conclude that the USA is the answer. The US at the moment is more militarily powerful than any other empire that ever existed. (Yes the actual USA is an empire by the common definition.) The USSR at its height would have given the current USA a run for its money through the use of nukes and sheer troop numbers, but given the current US military has 10 years+ of technological advantage, no contest.
If you mean powerful in comparison with contemporary powers, then historicaly there have been several empires that have been so far beyond anything in existenc that they could essentially take out anyone they could reach. I’d guess that by this standard Rome would be the answer. As powerful as the USA is right now, it still isn’t as powerful compare to its nearest rival as Rome was at its height.
In terms of relative, contemporary economic power I would say that Britain at its height wins. Britain also probably wins if you’re talking about power in terms of cultural influence.
Want to define the question a little better?
And before anyone comments, yes I know the British empire wasn’t contiguous. However the empire of Scotland, Ireland, Wales and England were. The fact that the economic power was derived from far flung colonies is irrelevant IMO.
Hm, sorry for the vagueness.
What I meant by most powerful is a combination of economic might, military power compared to its peers, vastness, cultural influence, longevity, and pretty much anything else that goes into making a country “great” or noteworthy or whatever.
Does that clear it up? Muddle it even more? Should this be moved to Great Debates?
I’m not sure. 
My goodness but that’s vague.
Yeah, it should be in GD I think. I can’t see how there can be any factual answer.
How much weight do you want to give to each criterion? Does the cultural and economic power of the British Empire outweigh the military might and geographic extent of the Roman?
How do we rank the US empire in term of longevity. My crystal ball is on the fritz so I don’t know whether it will last another 200 years or if it all ends next week. Assessing US cultural influence when we’re living in the middle of a transition to US dominated culture (forced or otherwise) is also going to be bit tough don’t you think? I’m sure most people would agree that US political and cultural influence is still in the growth phase ATM.
And why only contiguous empires? Why discount the true extent of the British Empire because there were oceans between the provinces?
I think I understand what you’re getting at, but it’s very hard to do a comparison. Alexander’s Macedonian/Greek Empire paved the way for Rome which paved the way for Britain which paved the way for the USA. Does that make the Macedonians the most culturally important?
I would suggest that there would be 4 serious contenders: Alexandrian, Roman, British and US. Great as the Soviet empire was, it’s going to go down in history as an adversary and an interesting social experiment, along with the Third Reich. The big 4 I listed had great military and economic power, but also changed world history and culture dramatically.
Then there have been a lot of regionally important empires such as China and the Aztecs and Inca, but there influence has been too limited to be serious contenders.
But I’m no historian and that’s just an opinion.
There is also the Mongols to consider, especially if the area of contiguous land under their control is to be taken as a factor.
By contiguous, I meant an unbroken reign of power. For example, ever since the Norman Conquest, England’s had a contiguous reign as a sovereign land. Am I using the term correctly or do I mean another word?
I’m sorry for the misunderstanding and the vagueness here… it’s 5:30am now and my earlier posts were made about 4:00am and so I’m not at peak efficiency here. I’ll probably be embarassed by this when I wake up tomorrow and reread it. Gah.
Christ, I’m an idiot. I just realized that the word I meant to use the entire time was continuous, not contiguous.
I don’t have to wait 'til tomorrow morning to feel a fool. 
Nah, it’s a fair enough use of the word. Because we were talking about empires I assumed you meant physically contiguous. My mistake.
In terms of area the British Empire is still the largest, having covered southern Asia, large parts of Africa, Australia, Canada and sundry smaller lands (This [cite says it had the largest population and area of any empire in any time up to the early 20th Century.)
In terms of population, it is probably now contemporary China (does it constitute an empire? It certainly controls a large number of different ethnic groups and allows most of its citizens little or no control over their government.)
[url=“http://www.hostkingdom.net/earthrul.html”]This site](http://www.oup.co.uk/isbn/0-19-873196-5) gives a number of figures for areas. It has (1st) British empire at 14,157,000 sq miles, (2) the Soviet Union and allies at 9,883,000 (13,800,000 including China, which seems debatable), (3 or possibly 2) the Mongols at 12,800,000, (4) the Spanish empire at 7,500,000, with the US 12th and the Romans 17th with 2,200,000 square miles.
Sorry, I’ll try again.
In terms of area the British Empire is still the largest, having covered southern Asia, large parts of Africa, Australia, Canada and sundry smaller lands (This webpage says it had the largest population and area of any empire in any time up to the early 20th Century.)
In terms of population, the biggest is probably now contemporary China (does it constitute an empire? It certainly controls a large number of different ethnic groups and allows most of its citizens little or no control over their government.) In contrast, the population peak of the British empire was well under than 1 billion (I can’t find accurate statistics, but most sources suggest it peaked around 1900 at 25% of the total global population of 1.6 bn.)
This site gives a number of figures for areas. It has (1st) British empire at 14,157,000 sq miles, (2) the Soviet Union and allies at 9,883,000 (13,800,000 including China, which seems debatable), (3 or possibly 2) the Mongols at 12,800,000, (4) the Spanish empire at 7,500,000, with the US 12th and the Romans 17th with 2,200,000 square miles.