40th century BC

Millennium:	4th millennium BC
Centuries:	41st century BC · 40th century BC · 39th century BC
Decades:	3990s BC 3980s BC 3970s BC 3960s BC 3950s BC 3940s BC 3930s BC 3920s BC 3910s BC 3900s BC
Categories:	Births – Deaths Establishments – Disestablishments

Events

c. 4000 BC, Liangzhu culture in China.
c. 4000 BC, More than 100 dwellings surrounding a community center, a cemetery and a kiln are built in Jiangzhai, near modern Xi'an, China.
Start of Naqada culture in Egypt.
Early Jōmon period begins on the islands of Japan.
Domestication of horses.
Plough in use.
Neolithic settlers begin to locate their communities at sites most easily defended, near rivers, on plateaus, or in swamps. For additional protection, they also frequently surround them with wooden walls, earth embankments and ditches.
Civilizations develop in the Mesopotamia/Fertile crescent region (around the location of modern day Iraq).
The first Korean civilization is founded around this era. According to myth, the founder is the son of a god and a she-bear who turned into a human.
Clay pots and vats discovered at a sprawling cave system in southern Armenia near the border with Iran shows signs of an organized effort to press and distill grapes during the Copper Age.

Bede began his history of the world with 3952 BC
In their ceremonial or commemorative proceedings, Freemasons add 4000 years to the current Anno Domini calendar year and append "Anno Lucis" ("Year of Light") to the year (i.e., 2011 AD = 6011 AL). This alternative calendar era, which would designate 4000 BC as "year zero", was created in the 18th century in deference to the Hebrew calendar's era dating system and other ideas regarding the year of creation at the time.

40th century BC
42nd century BC←41st century BC← ↔ →39th century BC→38th century BC