Empire ancient city-states of the Levant. Circa 1500 BC in China rose the Shang Empire which was succeeded by the Zhou Empire circa 1100 BC. Both surpassed in territory their contemporary Near Eastern empires. The Zhou Empire dissolved in 770 BC into feudal multi-state system which lasted for five and a half centuries until the universal conquest of Qin in 221 BC. The first empire comparable to Rome in organization was the Neo-Assyrian Empire (916–612 BC). The Median Empire was the first empire within the territory of Persia. By the 6th century BC, after having allied with the Babylonians to defeat
Historiography of the fall of the Western Roman Empire the cities, which became overpopulated. Roman cities were only designed to hold a certain number of people, and once they passed that, disease, water shortage and food shortage became common. Publishing several articles in the 1960s, the sociologist Seabury Colum Gilfillan advanced the argument that lead poisoning was a significant factor in the decline of the Roman Empire. Later, a posthumously published book elaborated on Gilfillan's work on this topic. Jerome Nriagu, a geochemist, argued in a 1983 book that "lead poisoning contributed to the decline of the Roman empire." His work centred on the level to which the ancient