Why do civilizations rise and fall?

One of the best explanations came from Ibn Khaldun, considered by many to be the father of the Social Sciences. He lived from 1332-1406, working as an Islamic scholar in Tunis, Fez, Granada, and Cairo.

Khaldun argues that each dynasty (or civilization) has within itself the seeds of its own downfall.

As the new dynasties establish themselves at the center of their empires, they become increasingly lax, less coordinated, disciplined and watchful. They become more concerned with maintaining their new power and lifestyle at the center of their empire. Their original internal cohesion and ties to the peripheral group dissolves into factionalism and individualism, diminishing their capacity as a political unit. Thus conditions are created wherein a new dynasty can emerge at the periphery of their control, grow strong, and effect a change in leadership, beginning the cycle anew. (from http://en.wikipedia.org/wiki/Asabiyyah#cite_note-tibi-2 )

This pattern can be seen throughout history. Rome was on the periphery of the Etruscan and Greek civilizations, and conquered both. The most recent change in the world's leading civilization (see www.sq.4mg.com/AppA.htm - this page ) was from the British Empire to the United States, one of its colonies. While the British may not have considered American colonials as barbarian, they definitely looked upon Washington, Lincoln, Rockefeller, and Ford as socially inferior.

The years in the chart above often relate to a decisive military result, such as Napoleon's 1814 abdication. But such exact dates may not reveal the full extent of a civilization in its prime. Mozart died 23 years before 1814, but his music is certainly part of the golden age of Vienna.

* Comment from a Greek viewer: I really wonder WHY Byzantines are TURKS. Sloan responds: Turkey is listed just as the current location. The Byzantines spoke Greek.

** The connection between City Size and Leading Civilizations. In the past, the largest cities of the world were often part of the leading civilization of the time, typically the capital city. This includes Memphis, Egypt in 3000 BC, Rome in 100 AD and New York City from 1925 to 1965. But leading civilizations did not always have the world's largest cities. The European Renaissance de-linked city size with being the leading civilization. The fact that Cairo of 1300 was a huge city did not make Egypt a leading civilization. But that did help its trading partner and sea power, Venice, become rich. For the next several centuries, Middle East and Asian cities grew large, while European nations became leading civilizations in the sciences and arts. It wasn't until 1830 that a European city (London) again became the world's most populous as well as most advanced. That was followed by technologically advanced New York and Tokyo. In the latter part of the 20th century, the world's largest cities have again become unrelated to leading civilizations, in places like Mexico City and Sao Paulo, Brazil. See https://en.wikipedia.org/wiki/List_of_largest_cities_throughout_history for 3 expert's opinions on the world's largest cities through time.

Top Ten Empires by Percentage of World Population--- from http://www.allempires.com/forum/forum_posts.asp?TID=27633

.....(the second millions figures below are the estimated world populations at the time)

Achaemenid Empire - 44.0% (49.4 million out of 112.4 million in the 5th century BC/480 BC)

Maurya Empire, India - 33.3% (50 million out of 150 million in the 2nd century BC)

Han Empire, China - 26.5% (59.6 million out of 226 million in 2 AD)

Roman Empire - 35.9% (80 million out of 223 million in the 2nd century AD)

Sassanid Empire, Persia - 37.1% (78 million out of 210 million in the 7th century AD)

Umayyad Caliphate - 29.5% (62 million out of 210 million in the 7th century AD) ?

Mongol Empire - 25.6% (110 million out of 429 million in the 13th century)

Ming Empire, China - 28.8% (160 million out of 556.2 million in 1600)

Mughal Empire, India - 29.2% (175 million out of 600 million[ in 1700)

Qing Empire, China - 36.6% (381 million out of 1.041 billion in 1820)

British Empire - 23% (460 million out of 2 billion in 1930)