Early Civilization 2500 BCE
By this date more major civilizations have appeared: Egypt in North Africa and the Indus Valley civilization in South Asia.
At this date farming is spreading around the Eastern Hemisphere, but as yet no urban, literate civilizations exist, and no large-scale states.
The first civilization has now appeared, in the Middle East.
By this date one of the major civilizations of the world, the Indus Valley civilization, has vanished - for reasons scholars still do not yet fully understand.
This era marks the high point of the Bronze Age world.
This has been a time of great upheaval - civilizations have been damaged, some even destroyed - but it is also a period of great progress.
New civilizations are developing, and old ones are changing, as such developments as Iron Age technology and the alphabet take hold.
In the Middle East, the Assyrian Empire has been replaced by three large states - the Babylonian Empire, the empire of the Medes, and a revived Egypt.
The Greek, Indian and Chinese civilizations are all entering their classical ages.