31st century BC
(32nd century BC - 31st century BC - 30th century BC - other centuries)(5th millennium BC - 4th millennium BC - 3rd millennium BC)
Events:
- 3000 BC - Menes unifies Upper and Lower Egypt, and a new capital is erected at Memphis.
- 3000 BC - Highly developed cities were to be found in the Indus valley civilization. See also Punjab and History of the Punjab.
- Ur-nina first king of Lagash in Mesopotamia
- Chinese ideograms
- Drainage and sewage system in India
- Dams, canals, stone sculptures using inclined plane and lever in Sumeria
- Pyramids in Ancient Egypt
- Copper was in use, both as tools and weapons.
- Crude writing existed in Egypt, and cuneiform writing was invented in Mesopotamia.