To Rule the Earth...
No one person has ever achieved rulership over the whole planet. Which states have come closest to this measure? What follows is a table of the largest states and empires to have held sway over the earth at one time or another. They are organized based on "greatest extent" - that portion of their history in which they possessed the largest amount of territory at a given time; but note well, in many instances a larger number is given afterwards, reflecting regions held at other times. The figures are approximations for the most part - many of these states held only vague or ill-defined frontiers. As a comparison to the land surface that is available, note that the habitable portion of the globe (i.e. excluding Antarctica) extends over roughly 52, 677,000 square miles (136,433,400 sq. km.): so, the largest of these entities reached about one quarter of the whole.
01 The British Empire and Commonwealth
The "greatest extent" of the British Empire was achieved between 1917 and 1922. The figures for "grand total" include the eastern seaboard of the United States, as well as other miscellaneous regions held by Britain, and subsequently lost or discarded before the expansion within the 19th and early 20th centuries.
Greatest extent
14,157,000 sq. miles (36,666,630 sq. km.)

Grand total, all eras
15,370,228 sq. miles (39,808,890 sq. km.)
02 The Soviet Empire
The Communist states were never entirely under a single ruler, although Josef Stalin probably came closest 1948-53. The main division was between the Soviet Bloc, led by Russia, and the Eastern Bloc, led by China. The area given for the whole Communist world does not include later, semi-nonaligned states such as Angola, Tanzania, or Laos.
The entire 
Communist world
13,800,000 sq. miles (35,742,000 sq. km.)
The Soviet Bloc 
(incl. Cuba)
09,883,591 sq. miles (25,598,500 sq. km.)
03 The Mongol Empire
The greatest extent of the Mongol hegemony was reached in roughly 1238-68. Some historical maps show the Mongol Empire in control of all of Siberia, but this is not so - a branch of the Mongols, The White Horde, did penetrate considerable portions of western Siberia, but no Mongol troops were sent into Yakut or Magadan, or anywhere near or above the Arctic Circle.
12,800,000 sq. miles (33,152,000 sq. km.)
04 The Spanish Colonial Empire
At its largest reach, roughly 1740-1790 Spain controlled about half of South America, more than a third of North America, and had significant holdings in the Pacific basin. It is sometimes asked: "Should not this figure be much higher, inasmuch as the Spanish and Portuguese colonial holdings were under a single authority at one point?" The short answer is: no - the Spanish and Portuguese crowns were united 1580-1640; at that time, Portuguese holdings in Brazil covered only the coastline, and some interior districts in the south. The entire Amazon basin was terra incognita, not even explored, let alone settled. The same can be said of Portuguese holdings in southern Africa.
07,500,000 sq. miles (19,425,000 sq. km.)
The Russian Federation
Russia is, of course, a subunit and the core of the Soviet Empire noted above. Even in its reduced state, it is still by far the largest single state on the planet.
06,592,000 sq. miles (17,073,280 sq. km.)
05 The Fascist Axis
The Axis powers of the World War II era were never under a single ruler, they were a group of three major powers and a handful of minor ones. Some of the lesser states were, in fact, only nominally associated with the Axis, owing to the needs of defence against mutual foes (as in the case of Finland, which I do not include), or outright intimidation, as in the case of Thailand (which I do). High tide of the Axis was during Aug.-Oct. 1942, when German troops were at the gates of Stalingrad, and less than 70 miles from Alexandria, Egypt; and Japanese troops had not yet been driven off Guadalcanal.
Japanese territory 
and conquests
02,864,000 sq. miles (07,417,760 sq. km.)
German territory 
and conquests
01,505,000 sq. miles (03,898,000 sq. km.)
Italian territory 
and conquests
01,451,066 sq. miles (03,732,341 sq. km.)
Other Axis allies 00,249,800 sq. miles (00,646,982 sq. km.)
total 06,069,866 sq. miles (15,695,083 sq. km.)
06 The Caliphate
The early Caliphate was a remarkable thing - a vast stretch of territory spanning Spain, North Africa, the Middle East, Iran, and much of Central Asia: all of which absorbed by Arab conquerors from 632 to 712 CE. Too vast to be stable, it began to fragment less than 200 years after.
05,100,000 sq. miles (13,209,000 sq. km.)
07 The French Colonial Empire
The French colonial experience was primarily within Africa, although there were significant territories in Asia and the Americas as well. The "greatest extent" figures cover what was held by France from c. 1905 to 1960. The "grand total" adds to that the earlier French colonial empire involving southern Quebec, much of the Mississippi-Great Lakes watercourses, the Canadian Maritime provinces, and French India.
Greatest extent
04,863,000 sq. miles (12,595,170 sq. km.)

Grand total, all eras
05,750,000 sq. miles (14,892,500 sq. km.)
08 The Chinese Empire
The "greatest extent" figures indicate the approximate size of the state governed by the Qing Emperors during the late 18th and early 19th centuries, which included Tibet, the Russian Far Eastern provinces, and Mongolia as dependencies. Grand Total includes territorial extensions into Central Asia in the 6th century CE, as well as early control over parts of northern Vietnam
Greatest extent
04,620,000 sq. miles (11,965,800 sq. km.)

Grand total, all eras
04,980,000 sq. miles (12,898,200 sq. km.)
09 United States of America
The United States greatest territorial extent was 1945-1946, when it occupied Japan, parts of Germany and Austria, and had not yet given independence to the Philippines. The grand total figures add various occupations and interventions in Latin America between the 1890's and 1934
Greatest extent
03,917,731 sq. miles (10,146,923 sq. km.)

Grand total, all eras
04,095,806 sq. miles (10,608,137 sq. km.)
10 Dominion of Canada
Canada is a subunit of the British Commonwealth and, as an independent state, the second largest on earth at this time.
03,849,000 sq. miles (09,968,910 sq. km.)
Peoples Republic of China
These figures reflect the current size of China, the 3rd largest state now in existence.
03,696,100 sq. miles (09,572,900 sq. km.)
United States of America
These figures reflect the current size of the United States (and possessions), the 4th largest state now in existence.
03,618,943 sq. miles (09,373,062 sq. km.)
11 The Portuguese Colonial Empire
At it's greatest extent, 1815-1822, Portugal controlled major territories in South America and Africa. The figures for "grand total" reflect not only the full extent of Portuguese African possessions in the 20th century as well as all of Brazil, but also the many fortifications and mercantile bases spread across the Indian Ocean in the 17th century. It will be noted that the "greatest extent" is barely larger than modern Brazil (immediately below), this is so inasmuch as Angola and Mozambique were merely small coastal districts in 1820.
Greatest extent
03,433,366 sq. miles (08,892,418 sq. km.)

Grand total, all eras
04,151,150 sq. miles (10,751,478 sq. km.)
12 Federative Republic of Brazil
Brazil is the major subunit of the Portuguese colonial empire, and remains today the fifth largest state in the world in terms of territory.
03,300,171 sq. miles (08,547,404 sq. km.)
13 Commonwealth of Australia
This continent-sized land mass hosts but a single state, the 6th largest today, and one which is significantly larger than all the great empires of classical times. The greatest extent figures are for the period 1918-1975, when Australia administered Papua and New Guinea.
Greatest extent
03,147,700 sq. miles (08,152,550 sq. km.)

Current size
02,969,910 sq. miles (08,152,550 sq. km.)
14 The Uighur Khaghanate
A vast, amorphous territory in southern Siberia, Mongolia, Manchuria, eastern Khazakhstan, and parts of Xinjiang, the Uighurs (an early Turkic people) ruled this region after the disintegration of the Gök Turks (#30) in 630 CE. The era of their greatest influence was roughly 760 to 795 CE. The disintegrated themselves in the 850's.
03,000,000 sq. miles (07,770,000 sq. km.)
15 Japanese Empire
Repeated from #5 above, but it deserves a slot of it's own. Japan was for almost it's entire history confined to the Home Islands, but in the first half of the 20th Century a complicated interweaving of geopolitical circumstances precipitated a sudden expansion throughout the Far East and the Pacific. The peak was reached between June and October of 1942.
02,864,000 sq. miles (07,417,760 sq. km.)
16 The Persian Empire
This is the oldest of the super-states listed herein - it is the vast empire successfully held off by the Greek city-states in the 5th century BCE.
02,382,000 sq. miles (06,169,380 sq. km.)
17 The Seljuq Empire
The Seljuqs were a Turkish people who established a Middle Eastern Empire in the late 11th century CE. It swiftly fragmented into more localized spheres of influence, notably in Iran, Anatolia, and the Fertile Crescent region.
02,300,000 sq. miles (05,957,000 sq. km.)
18 The Roman Empire
The Romans were at their greatest extent in the early 2nd century of the Common Era, when Trajan briefly annexed Mesopotamia. The Byzantine (East Roman) Empire should be regarded as a subset of this - they never expanded beyond the boundaries of the earlier state.
02,200,000 sq. miles (05,698,000 sq. km.)
19 The Ottoman Empire
The Osmanli Turks established a state in Bithynia which eventually grew to encompass Anatolia, the Levant, the Balkans, North Africa, Crimea, the Caucasus, and western Arabia as far south as Yemen.
02,160,000 sq. miles (05,594,400 sq. km.)
20 The Macedonian Empire
Alexander the Great briefly established a vast empire on the carcase of the Persian super-state (#15); but it fragmented almost immediately after his death.
02,100,000 sq. miles (05,439,000 sq. km.)
21 Mexico
When Mexico became independent (first as an Empire and shortly thereafter a republic) in 1821, it inherited a vast stretch of former Spanish claims reaching from Nevada to Costa Rica. The figures are for the period 1821-23, after which Central America broke away.
01,890,983 sq. miles (04,871,733 sq. km.)
22European Union
Not an empire in the sense usually used by this page, the EU is a confederation of associate states, most of whom are members of a customs and monetary union, but nevertheless retain considerable autonomy, particularly in foreign affairs. Still, the EU is a definable territory and an organized entity, and therefore deserves mention here.
01,669,807 sq. miles (04,324,782 sq. km.)
23 Germany
Repeated from #5 above, but it deserves a slot of it's own. Nazi Germany expanded to include most of Europe and a slice of North Africa at one point. The peak was achieved Aug.-Sept. 1942. Also included as a separate entry is Germany's colonial empire of the early 20th century, which wasn't nearly as large as the British or French, but was still respectable in size - Germany held several large possessions in subsaharan Africa, as well as a number of islands in the South Pacific; also included are the provinces of Imperial Germany in Europe, mostly Polish.

Greatest extent (Sept. 1942)
01,505,000 sq. miles (03,898,000 sq. km.)

Colonial Empire (c. 1902-1914)
01,271,000 sq. miles (03,291,900 sq. km.)

Grand total, all eras
02,559,070 sq. miles (06,627,991 sq. km.)
24 Almoravid Empire
The Almoravids were a western Berber folk who boiled out of Mauretania in the 11th century, to rapidly encompass all of northwestern Africa and about half of Spain-Portugal for a brief time. Establishing a radically puritanical sect of Islam, and founding the city of Marrakesh in 1065, they were at the height of their influence c. 1105-1145.
01,500,000 sq. miles (03,885,000 sq. km.)
25 Italian Empire 
Repeated from #5 above, but it deserves a slot of it's own. Italy never developed an extensive colonial empire in the manner of Great Britain or France, but in the 1930's it became expansionistic, and added to such overseas possessions as it had obtained a considerably larger expanse. The king at the time, Victor Emmanuel III, was induced to assume the style of "Emperor", but the real power lay with Benito Mussolini. The largest acquisitions were Libya and Ethiopia, but smaller territories in Somalia, the Aegean, and Albania are also included. The time period extended from 1936 to 1941.
01,451,066 sq. miles (03,732,341 sq. km.)
26 Timur's Empire
Timur the Lame was a tribal leader of Mongol extraction who set up a Middle Eastern empire centered around Transoxania and Iran in the period between 1380 and 1405.
  1,445,000 sq. miles (03,742,550 sq. km.)
27 The Mughal Empire
There have been large, centralized states on the Indian subcontinent for a very long while - the Mughal empire in the latter half of the 17th century probably achieved the greatest size, although the current republic isn't much smaller. Also given are figures for the Indian Empire during the days of the Raj, which included not only all of modern India, but also Pakistan, Bangladesh, and the Himalayan kingdoms.
Mughal Empire, c. 1650
01,425,000 sq. miles ( 2,294,250 sq. km.)

British Raj c. 1877-1948
01,661,571 sq. miles ( 4,303,468 sq. km.)
28 The Golden Horde (Ulus Juchi)
This was the western Horde of the Mongols, which conquered most of Russia and the Ukraine, and penetrated central Europe. The two figures given reflect, first, the maximum size of the state after it had broken from the Imperial line but before it began to fragment, approximately 1300-1380; and second, the maximum size while it was still an arm of the Imperial Mongols, Feb.-Dec. 1241.
Greatest extent (independent)
01,400,000 sq. miles (03,431,750 sq. km.)

Greatest extent (as Mongol Imperial vassal)
01,565,000 sq. miles (03,431,750 sq. km.)
29 The Seleucid Empire
The Seleucid state was a successor empire to Alexander's Macedonian Empire (#20). At it's greatest extent, it reached from western Anatolia to Afghanistan.
01,325,000 sq. miles (03,431,750 sq. km.)
30 Chagatai Horde (Ulus Jagatay)
Emerging as a particular sub-horde under the Mongols, in 1227. They remained within Mongol hegemony until unity shattered c. 1335. Afterward, the Chagatai briefly held most of Xinjiang, about half of Khazakhstan, Kyrgystan, and much of Uzbekstan, before fragmenting into Eastern and Western Hordes in 1348.
01,300,000 sq. miles (03,367,000 sq. km.)
Republic of India
The modern Indian state, successor to the Mughals and the Raj, the 7th largest country in the world.
01,222,243 sq. miles (03,165,596 sq. km.)
31 The Gök Turkiut
These were an early Siberian Horde, successors to the Juan-Juan (#36). They were the direct ancestors of subsequent and modern Turkic peoples, and ruled the southern Siberian and Mongolian Steppe in the late 5th, 6th, and early 7th centuries CE, before disintegrating into Eastern and Western Hordes, each later to be subsumed by neighbouring enemies. The Turks re-emerged as a major force with the Seljuqs (# 17, above) in the 11th century.
01,160,000 sq. miles (03,004,400 sq. km.)
32 The Huns
The Huns were the western horde of a numerous group of Central Asians - in China they were called the Hsiung-Nu, and an Indian group was called the Hunas. The Western Huns migrated across the Volga in the 4th century and into the Ukraine, thence into Europe. They were at their height under Attila the Scourge c. 450-455. They can only with difficulty be called an Empire - the frontiers were quite amorphous, there were Hunnic groups which were not under the hegemony of Attila, and the Huns can scarcely be said to have set up a working infrastructure. Still, for what it's worth, they did seize a wide stretch of territory across central Europe and the Balkans, and controlled the destinies of many tribes and nations for a time.
01,100,000 sq. miles (02,849,000 sq. km.)
33 Argentine Republic
Eighth largest modern state. Aside from the Andean highlands, Argentina encompasses all the southernmost reach of South America.
01,073,400 sq. miles (02,780,106 sq. km.)
34 Republic of Kazakhstan
Ninth largest modern state. Kazakhstan is a vast semi-arid region of central Asia, and a subunit within the Soviet Empire up until its independence in 1991.
01,052,090 sq. miles (02,724,913 sq. km.)
35 The Ghaznavid Empire
A Mediaeval state within what is now Afghanistan, Pakistan, portions of central Asia, and eastern Iran. It's greatest extent was in the early 11th century.
01,000,000 sq. miles (02,590,000 sq. km.)
36 The Juan-Juan
This was a Siberian Horde of obscure ethnicity (they have been variously identified as proto-Turks, proto-Mongols, or even early Avars) whose greatest extent encompassed a reach of territory across much of Manchuria, Mongolia, and eastern Khazakhstan - they were at the height of their power in the 5th century CE.
00,982,000 sq. miles (02,543,380 sq. km.)

Addenda - famous empires of smaller size: The following are well-known states which, despite their notoriety, never reached the 1,000,000 sq. mile/2.500,000 sq. km. extent detailed just above. Included for comparison are all modern states in excess of 1.5 million sq. km., and the five largest American states.


    I have sometimes been asked why these figures apparently don't reflect Antarctic claims. I'll admit it straight out, I am deliberately ignoring Antarctica. My reasons for doing so are twofold:
    1). Although several nations have advanced territorial claims to the continent - in fact, several of these claims overlap considerably - all participants have agreed not to directly pursue such claims until such time as a conference should be organized to settle the matter. Thus, all claims are now, and have been for quite some time, not precisely in limbo, but at least in abeyance for the time being. Indeed, there is a considerable wedge of Antarctica which remains unclaimed by all, the last region of genuinely unclaimed land (well, land of a sort...) left on Earth (but don't you and your closest friends run out and buy an icebreaker and a flagpole - because the question of territorial claims is being held in suspension at the moment, the Antarctic participant governments have agreed not to recognize, or permit, any further claims being made).
    2). There is virtually nobody there. The "To Rule The Earth" file records the widest-reaching systems of governance achieved by mankind, and I feel that "governance" requires a governed, a stable and permanent population dwelling in the regions referred to. Although there have been a few births in Antartica - at least ten since 1978 - it still has no "native" population. And, there cannot at this time be a native population - without massive and ubiquitous infrastructure, the place is completely uninhabitable. Everyone there is scientific or military personnel assigned to the place for a tour of duty. Thus, the place resembles more a spaceship or a naval vessel than it does a potentially habitable landmass.

The Carolingian Empire
    The Frankish people emerged out of the Dark Ages with a unified state, and a dynamic new dynasty. That family's most illustrious scion, Charlemagne, extended the reach of the Franks to include almost all of western Europe, from Hungary to Brittany and from Hamburg to Pamplona. Further, Charles fostered a rebirth of learning, and was thus instrumental in shaping, both politically and culturally, the beginning of the Mediaeval era from out of the crumbled wreckage of the Roman Empire in the West. Alas, western Europe simply isn't that vast in terms of area, and so this vitally significant empire doesn't even come close to the list above - Charlemagne at the height of his influence (c. 790-814) controlled no more than around 575,000 sq. miles (1,489,250 sq. km.), close but not quite the size of Alaska.

The Incan Empire
    I am asked at fairly regular intervals about a possibly missing element in this list, namely, Tiwantinsuya, the Incan Empire of the later 15th and early 16th centuries. Correspondents will mention figures ranging anywhere from 2.5 million square miles (6.475 sq. km.) to 7.5 million square miles (19.425 sq. km.). Some writers have cited a book by Charles Mann called "1491", a description of the Western Hemisphere just before the arrival of Europeans) in support of their contention - apparently Mann alleges that the Inca controlled a region comparable in size to that of the Ottoman or Roman Empires.
    I must disagree with Mr. Mann. Let's do the math - assume half of Peru (actually, historical maps that I've consulted usually give less than that, about 1/3 to 40 percent, but we'll assume half), that yields about 250,000 sq. miles. Assume all of Ecuador, another 100,000. Assume about 1/3 of Bolivia; that will give about 130,000. Add maybe half of Chile (most maps I've seen aren't as generous), another 150,000. And add perhaps the northern tip of Argentina, maybe 1/10 for another 100,000. Under these generous assumptions, the total comes to about 730,000. If you want to throw in some smidgens of Colombia, you could maybe push 750,000, very close to the size of modern Mexico. You would have to toss in all the rest of Peru just to reach 1 million, something historical works never do because the Inca aren't known to have penetrated to any significant extent into the Amazon Basin. As for the highest figures I've seen (7.5 million sq. miles), well, all of South America only comes to 6.89 million - the 7.5 million figure is about identical to the entirety of the Spanish colonial Empire at it's greatest extent (#4 above), from Patagonia to Utah; I'm certain the later Maya, the Aztecs, and the early Apache would be astonished to learn that they were subjects of Cuzco.
    The simple fact of the matter is that the domain of the Inca wasn't enormous (the Aztec territory was even smaller) physically, albeit it's influence and power were great. But size isn't everything - consider the clout and influence of the Vatican as compared to it's physical area...

Most participation
    An interesting question arises: which area of the globe has been a province in the largest number of these empires over the centuries? The answer will perhaps be not especially surprising: the Levant; specifically, that region of the eastern Mediterranean shore between Antioch and Sinai. Of the 47 empires listed, this region has been occupied by 13 of them, The British (in the Holy Land and Jordan - the French in Lebanon and Syria), the Caliphs, Persia, the Seljuqs, the Romans/Byzantines, the Ottoman Turks, Macedonia, the Seleucids, Assyria, Egypt, Babylon, and the Antigonid Empire. Truly, this region is the Over-Promised Land.

Methodology and Sources
    This is my own work, compiled from a variety of secondary sources. I consulted various historical atlases and built up a list of major sovereign entities, and then calculated land area using almanacs and similar works; I calculated in provincial or district areas when frontiers were at variance with modern ones, and used applied geometry in instances where no comparative analysis was available otherwise. My most significant sources were: **************************************************