The earliest known wheels, from the mid-fourth millennium BCE, appear first as potters' wheels and then as solid wooden discs paired on axles to make carts and wagons, attested across Mesopotamia and Central Europe. Turning a wheel on a fixed axle allowed loads to be rolled rather than dragged, multiplying what a person or animal could move. Wheeled vehicles spread alongside the domestication of draught animals.
By enabling wheeled transport of goods and people, the wheel raised the volume of produce, materials and trade that towns could draw in and distribute, supporting larger and better-supplied settlements.