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Throughout history much of the world has been ruled by empires.To be considered an empire an expanse of land must be politically led by either a monarch, an emperor, or be an oligarchy.
As the decline of the U.S. is being hailed in the news and opinion of the world, we thought it would be interesting to look at the biggest empires of the past.
Aside from their leadership model, the only other thing they all have in common is that each of them disappeared.
The Rashidun Caliphate covered over 3 million square miles of land - almost 6% of the earth's land-mass.
This empire began when Mohammad died in 632 AD and his followers scrambled to acquire his empire while the great prophets family prepared for his funeral.
Despite being a Caliphate or religiously governed empire, the conquered of other faiths were given good treatment.
They were allowed freedom to practice their own religion as long as they paid taxes to the Caliph.
The Portuguese Empire was the first global empire in history, as well as the longest-lived modern European colonial empires.
The empire began with the capture of Ceuta in 1415 and ended in 1999 with the handover of Macau. The empire's most valuable colony, Brazil, won its independence in 1822. Following a war in 1974 to overthrow the regime, the empire's government recognised the independence of all its colonies, except for Macau. Macau was returned to China in 1999.
The Abbasid Caliphate covered 4.29 million square miles of land - more than 7% of the earth's landmass.
The empire had an unknown population number in 750 and claimed Baghdad as its capital.
While population numbers are unknown, the empire lasted from 750 to 1258 and only went into decline as the Turkish army rose to power.
The Umayyad Caliphate covered 5.02 million square miles of land - more than 8% of the earth's landmass.
The empire had 62 million people between 720 and 750 -- nearly 30% of the world's population.
The second Islamic caliphate was founded in Arabia after the Prophet Muhammad's death and while the Umayyad family originated in Mecca but chose Damascus as its capital.
The Umayyad Caliphate, whose name comes from the great-grandfather of the first Umayyad caliph, ruled between 661 and 750 A.D.
The Yuan Dynasty covered 5.41 million square miles of land - more than 9% of the earth's landmass.
The empire had almost 60 million people in 1291 -- about 17% of the world's population.
The Yuan Dynasty, which was founded by the grandson of Genghis Khan, began in 1271.
Five years after founding the dynasty, Kublai Khan captured the capital of the rival Southern Song Dynasty and unified all of China. The dynasty enjoyed a bountiful life, encouraging trade with foreign countries as well as a visit from famed Italian merchant Marco Polo.
The Qing Dynasty covered 5.68 million square miles of land - nearly 10% of the earth's landmass.
The empire had more than 432 million people in 1851 -- more than 35% of the world's population.
Founded when the Chinese defeated the Mongols, the Qing Dynasty ruled China from the 17th to the 20th century, with the height of its power and reach peaking in the 1800s. The Republic of China took over the government at the end of the Qing Dynasty
The Spanish Empire covered 7.72 million square miles of land - more than 13% of the earth's landmass.
The empire had 68.2 million people between 1740 and 1790 -- about 12% of the world's population.
Spain's empire began in the days of Columbus and lasted, in parts of Africa, until the latter 20th century. Spanish is now the second most spoken language in the world.
The Russian Empire covered 9.15 million square miles of land - more than 15% of the earth's landmass.
The empire had 176.4 million people in 1913 -- more than 9% of the world's population.
Russia was the last absolute monarchy in Europe, and prior to World War I, one of five great powers in Europe. During the time of the empire. society was strictly segregated into five social estates. The Russian Empire ended with the bloody Russian Revolution of 1917.
The Mongol Empire covered 9.15 million square miles of land - more than 16% of the earth's landmass.The empire had 110 million people between 1270 and 1309 -- more than 25% of the world's population.
The largest contiguous empire in history, the Mongol Empire emerged from the unification of Mongol and Turkish tribes under Genghis Khan. The Mongols achieved advancements in various technologies and ideologies during the empire.
In 1331, the Black Death began its rampage in Mongolia and brought the Empire into its long, slow decline that culminated with its annexation by Russia in 1783
The British Empire covered 13.01 million square miles of land - more than 22% of the earth's landmass.The empire had 458 million people in 1938 -- more than 20% of the world's population.
The British Empire began with overseas colonies and trading posts and in the end comprised dominions, protectorates, and mandates, as well.
It was made up of 13 million square miles of land - more than 22% of the earth's land-mass. In 1922, the Empire had a population of 458 million people or about 20% the global population.
The financial burden of World War I was the beginning of the end for the British Empire.
Japan's occupation of its territories in the Second World War and the loss of India in 1947 brought the days of the British Empire to a close.
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