Linzi, China
Linzi was the capital of the State of Qi from the 9th century BC until the 3rd century BC, encompassing a period called the Warring States - named because China was in a state of total war during this period. The cities embroiled in this war needed to have heavy defences, and a strictly controlled population. The system was therefore authoritarian, with the government registering all the citizens in their city so they could be taxed and drafted into labour or military service. The development of cast iron tools made it possible for farmers to drastically increase their output of food, which allowed more growth. Trade was essential to Linzi, though the markets were strictly monitored and controlled by the state. Today, the Linzi District is a part of modern Shandong, in Eastern China, where excavations have taken place.