What where the ancient civilizations?

The Aztecs in South America, Mayans in Central America, Incans in Peru, Romans in Europe, Egyptians in northern Africa, Babylonians, Assyrians, Sumerians, and Persians in modern Iraq, Greeks in Greece, Chinese in China (longest-lasting empire in the world, too), and probably many others that I didn't mention.
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Civilizations in this context I will be assuming to be complex societies that are categorized by having an increasingly dominant social form (e.g. complex division of people into different jobs/roles, the emergency of literacy and literate class normally characterized by a political and religious hierarchies, monumental public buildings that were built using skilled labour all supported by a particularly intensive agricultural system to support it all meaning they are all located near fresh water bodies/rivers. Ancient Civilizations are deemed to have emerged around 6,000 years ago in four main regions:
  1. The Lower Tigris and Euphrates Valley (Summerian/Mesopotamia Civilization);
  2. The valley of the Nile (Ancient Egypt Civilization);
  3. The Indus Valley around Harappa and Mohenjo-Daro (Indus Civilization);
  4. The Yellow River around An-yang (Chinese Civilization).


The early civilizations of America (Inca/Mayan Civilizations), Greeks (Minoan/Mycenaean Civilizations), Korean, Persia, Romans emerged considerably later, and are not considered ancient.