The 4th millennium BC spanned the years 4000 BC to 3001 BC. It marked a critical turning point in human history, characterized by the transition from late Neolithic agricultural societies into urban, state-level civilizations.
This millennium witnessed the invention of writing, the initial spread of bronze metallurgy, the adoption of the wheeled vehicle, and the rise of the first primary states in Mesopotamia and Ancient Egypt, effectively initiating recorded history.
The city states of Sumer and the (Predynastic) Kingdom of Egypt were established and grew to prominence. Agriculture spread widely across Eurasia.
World population growth relaxed after the burst that came about from the Neolithic Revolution. World population was largely stable in this time at roughly 50 million, growing at an average of 0.027% per year.
c. 3250 BC – Potter's wheel in use in Ancient Near East
4100–3100 BC – the Uruk period, with emerging Sumerian hegemony during the Uruk Expansion and development of Proto-cuneiform writing; base-60 mathematics, astronomy and astrology, civil law, complex hydrology, the sailboat, potter's wheel and wheel; the Chalcolithic proceeds into the Early Bronze Age. Dams, canals, stone sculptures using inclined plane and lever in Sumer and the Tigris–Euphrates Valley
c. 3100 BC?: The Anu Ziggurat and White Temple are built in Uruk.
3500–2340 BC – Sumer: wheeled carts, potter's wheel, White Temple ziggurat, bronze tools and weapons.
First to Fourth dynasty of Kish in Mesopotamia.
Sumerian temple of Inanna at Eridu erected.
Temple at Al-Ubaid and tomb of Mes-Kalam-Dug built near Ur, Chaldea.
c. 3700 BC In the city of Uruk, groups of tokens representing commercial transactions begin to be enclosed in hollow clay balls and kept in archives.
3300 BC to 3000 BC: Face of a woman, from Uruk (modern Warka, Iraq) is made; it is now in the Iraq Museum, Baghdad (stolen and recovered in 2003)
Ubaid period came to an abrupt end in eastern Arabia and the Oman peninsula at 3800 BC.
3000 BC – Tin is in use in Mesopotamia soon after this time.
The cuneiform script proper emerges from pictographic proto-writing in the later 4th millennium. Mesopotamia's "proto-literate" period spans the 35th to 32nd centuries BC. The first documents unequivocally written in the Sumerian language date to the 31st century BC, found at Jemdet Nasr.
Kura-Araxes culture expands Southwards towards Sumer.
Possible reigns of Lugalbanda and Enmerkar prior to 3250 BC.