Most of the Indus settlements had been abandoned or had shrunk in size by about 1800 BCE. Many factors contributed to the end of the Indus civilization, but climate change is emerging as a primary ...

"These results clearly support the hypothesis that the first state structures developed around 1800 BCE in Western Europe," ...

There are also many great examples in the Metropolitan Museum in NY. In 1887, the British archeologist Flinders Petrie discovered an Egyptian doll factory dating to 1800 BCE.