Chinese River Valley civilization<span>although it was from 8000 to 2000 BCE
They used the river for irrigation and they raised pigs and chickens. Used stone tools</span>
I believe there are lots of reasons why the Roman Empire declined but the 3 most important ones are, Government corruption and political instability, Invasions by Barbarian tribes, and The rise of the Eastern Empire, but the one I think is the most important is the first one reason.
