The Largest Empires in History, by Peak Land Area

History · Published 2026-10-20

Map of Europe and the Mediterranean with the territory of the Roman Empire shaded in green — The Roman Empire at its greatest extent under Trajan, around 117 AD, shaded in green. Map: Joyfulmapper, CC0.

By land area at its peak, the largest empire in history was the British Empire, at roughly 35.5 million square kilometres around 1920. The Mongol Empire, at about 24 million km² in the late 13th century, was the largest contiguous land empire. Both figures are scholarly estimates, and the further back you go, the rougher they become.

Where the numbers come from

Almost every ranking of empires you will meet, from encyclopaedia lists to quiz books, traces back to a small number of academic compilations. The most important are the work of the political scientist Rein Taagepera, who in a series of papers (1978, 1979 and 1997) estimated the territory of large states century by century, and a 2006 paper by Peter Turchin, Jonathan Adams and Thomas Hall that compiled peak areas for about 60 historical empires to study why they tended to stretch east–west.

Taagepera measured areas from historical atlases, typically counting land over which a state exerted at least some control or tribute. That choice matters. A steppe empire that collected tribute from loosely held regions looks much bigger by this measure than by a stricter standard of direct administration. Colonial empires raise another question: does a protectorate count, or a claimed but unexplored interior? The figures below are therefore best read as "of the order of", not as exact surveys.

The largest empires at their peak

The table lists commonly cited peak areas, rounded as in the sources. Where both Taagepera and Turchin, Adams and Hall give a figure, they broadly agree.

Empire	Peak area (million km²)	Approx. year of peak	Main source of estimate
British Empire	35.5	1920	Taagepera 1997
Mongol Empire	24.0	c. 1270–1309	Taagepera 1997; Turchin et al. 2006
Russian Empire	22.8	1895	Taagepera 1997; Turchin et al. 2006
Qing dynasty (China)	14.7	1790	Taagepera 1997; Turchin et al. 2006
Spanish Empire	13.7	1810	Taagepera 1997
Second French colonial empire	11.5	1920	Taagepera 1997
Abbasid Caliphate	11.1	750	Taagepera 1997
Umayyad Caliphate	11.1	720	Taagepera 1997
Yuan dynasty	11.0	1310	Taagepera 1997
Xiongnu	9.0	176 BC	Taagepera 1979; Turchin et al. 2006
Ming dynasty	6.5	1450	Taagepera 1997; Turchin et al. 2006
Rashidun Caliphate	6.4	655	Taagepera 1997
Achaemenid Persian Empire	5.5	500 BC	Taagepera 1979; Turchin et al. 2006
Tang dynasty	5.4	715	Taagepera 1997; Turchin et al. 2006
Macedonian Empire (Alexander)	5.2	323 BC	Taagepera 1979; Turchin et al. 2006
Ottoman Empire	5.2	1683	Taagepera 1997; Turchin et al. 2006
Roman Empire	5.0	117	Taagepera 1979; Turchin et al. 2006

For scale: Earth's land surface is about 149 million km², or roughly 135 million km² if Antarctica is left out. On the second basis, the British Empire's 35.5 million km² works out at about a quarter of the world's land.

Notes on the top of the list

British Empire

The British peak is usually dated to just after the First World War, when mandates over former Ottoman and German territories were added to the dominions, colonies and protectorates already held. The figure includes self-governing dominions such as Canada and Australia, which accounts for a large share of the area. The peak was brief in historical terms: the dominions were already largely self-governing, and the empire contracted rapidly after the Second World War as colonies became independent states.

Mongol Empire

Founded by Chinggis (Genghis) Khan in 1206, the Mongol Empire expanded across Eurasia within two generations. By the later 13th century it had split into four successor states (the Yuan in China, the Ilkhanate in Persia, the Chagatai Khanate in Central Asia and the Golden Horde, or Jochi Ulus, on the western steppe). That is why its peak is given as a range: some estimates treat the successor khanates together, others measure the unified state before the split. Either way it remains the largest empire whose territory was one continuous block of land.

Russian Empire

The Russian Empire grew overland, eastward across Siberia to the Pacific and south into Central Asia and the Caucasus. Its late-19th-century extent of about 22.8 million km² is slightly larger than the later Soviet Union's roughly 22.4 million km², mainly because the empire included the Grand Duchy of Finland and the Polish lands it ruled, which the Soviet state did not keep. Alaska, sold to the United States in 1867, was already gone by the 1895 benchmark.

Why rankings differ from list to list

Peak versus average. An empire's maximum extent may have lasted only a few years. Taagepera also studied duration; some empires that rank modestly by peak area held their land for far longer.
Control versus claim. Spain claimed huge areas of the Americas that it never administered. Some compilations count claims, others do not.
Which state is "the" empire. Is the Yuan dynasty part of the Mongol Empire or a separate state? Are the Eastern and Western Han one entry or two? Different lists split and lump differently.
Population is a different ranking. Measured by share of the world's people, the order changes again; large, thinly populated territories in Siberia or Canada count for much less.

How to use these figures: quote them with "about" or "roughly", name the source ("according to Taagepera's estimates"), and avoid ranking empires that are within a few hundred thousand km² of each other. Differences that small are inside the margin of error.

Quick quiz: empires

Sources

Taagepera, R. (1997). "Expansion and Contraction Patterns of Large Polities: Context for Russia." International Studies Quarterly 41(3): 475–504. doi:10.1111/0020-8833.00053
Taagepera, R. (1979). "Size and Duration of Empires: Growth-Decline Curves, 600 B.C. to 600 A.D." Social Science History 3(3/4): 115–138.
Turchin, P., Adams, J. M. and Hall, T. D. (2006). "East-West Orientation of Historical Empires and Modern States." Journal of World-Systems Research 12(2): 219–229. doi:10.5195/jwsr.2006.369
Wikipedia, List of largest empires (compilation of the above estimates, consulted October 2026).
Encyclopaedia Britannica, Mongol empire.