The wheel is believed to date to the Neolithic period (about 12,000 years ago) appearing at different stages in different civilizations. The earliest use was probably for turning pottery; Mesopotamian diagrams show that use as early as 3500 B.C.
A wheel with spokes first appeared on Sumarian chariots around 2000 B.C., and wheels seem to have developed in Europe by 1400 B.C. After about 400 B.C. Nubians used wheels to turn pottery and as water wheels. The earliest record of a wheelbarrow comes from China in the Three Kingdoms period (A.D. 184-280).
The absence of passable roads likely delayed wide usage of the wheel. Carrying goods on the back would have been the preferred method of transportation over surfaces that contained many obstacles. In less developed areas, the lack of developed roads prevented wide usage of the wheel for transportation well into the 20th century.
The invention of the wheel has also been important to technology in general. Important applications include the water wheel, cogwheel and spinning wheel. More modern descendants of the wheel include the propeller, jet engine, flywheel and turbine.
The wheel alone is not a machine, but when attached to an axle in conjunction with a bearing, it forms the wheel and axle, one of six simple machines identified by Renaissance scientists: lever, wheel and axle, pulley, inclined plane, wedge and screw. FC